[test] add script to test which diag commands RCP supports

This commit implements a test script tools/cp-caps/rcp_caps_test.py
to test which diag commands RCP supports using the DUT and reference device.

tools/cp-caps/README.md

@@ -0,0 +1,130 @@
+# RCP Capabilities Test
+
+This test is used for testing RCP capabilities.
+
+## Test Topology
+
+```
+                    +-------+
+    +---------------|  PC   |----------------+
+    |               +-------+                |
+    | ADB/SSH                                | ADB/SSH/SERIAL
+    |                                        |
++-------+                           +------------------+
+|  DUT  |<-----------Thread-------->| Reference Device |
++-------+                           +------------------+
+
+```
+
+- PC : The computer to run the test script.
+- DUT : The device under test.
+- Reference Device : The device that supports all tested features.
+
+### Python Dependences
+
+Before running the test script on PC, testers should install dependences first.
+
+```bash
+$ cd tools/otci
+$ pip install build
+$ python -m build
+$ pip install dist/otci_openthread-0.0.1-py3-none-any.whl
+$ pip install adb-shell
+$ pip install adb-shell[usb]
+```
+
+### Reference Device
+
+The [nRF52840DK][ot-nrf528xx-nrf52840] is set as the reference device by default. Testers can also select the other Thread device as the reference device.
+
+[ot-nrf528xx-nrf52840]: https://github.com/openthread/ot-nrf528xx/blob/main/src/nrf52840/README.md
+
+Quick guide to setting up the nRF52840DK:
+
+```bash
+$ git clone [email protected]:openthread/ot-nrf528xx.git
+$ cd ot-nrf528xx/
+$ git submodule update --init
+$ ./script/bootstrap
+$ ./script/build nrf52840 UART_trans -DOT_DIAGNOSTIC=ON
+$ arm-none-eabi-objcopy -O ihex build/bin/ot-cli-ftd ot-cli-ftd.hex
+$ nrfjprog -f nrf52 --chiperase --program ot-cli-ftd.hex --reset
+```
+
+## Test Commands
+
+### Help
+
+Show help info.
+
+```bash
+$ python3 ./tools/cp-caps/rcp_caps_test.py -h
+usage: rcp_caps_test.py [-h] [-d] [-v]
+
+This script is used for testing RCP capabilities.
+
+options:
+  -h, --help           show this help message and exit
+  -d, --diag-commands  test whether the RCP supports all diag commands
+  -v, --verbose        output verbose information
+
+Device Interfaces:
+  DUT_SSH=<device_ip>            Connect to the DUT via ssh
+  DUT_ADB_TCP=<device_ip>        Connect to the DUT via adb tcp
+  DUT_ADB_USB=<serial_number>    Connect to the DUT via adb usb
+  REF_CLI_SERIAL=<serial_device> Connect to the reference device via cli serial port
+  REF_ADB_USB=<serial_number>    Connect to the reference device via adb usb
+  REF_SSH=<device_ip>            Connect to the reference device via ssh
+
+Example:
+  DUT_ADB_USB=1169UC2F2T0M95OR REF_CLI_SERIAL=/dev/ttyACM0 python3 ./tools/cp-caps/rcp_caps_test.py -d
+```
+
+### Test Diag Commands
+
+The parameter `-d` or `--diag-commands` starts to test all diag commands.
+
+Following environment variables are used to configure diag command paremters:
+
+- DUT_DIAG_GPIO: Diag gpio value. The default value is `0` if it is not set.
+- DUT_DIAG_RAW_POWER_SETTING: Diag raw power setting value. The default value is `112233` if it is not set.
+- DUT_DIAG_POWER: Diag power value. The default value is `10` if it is not set.
+
+> Note: If you meet the error `LIBUSB_ERROR_BUSY` when you are using the ADB usb interface, please run the command `adb kill-server` to kill the adb server.
+
+```bash
+$ DUT_ADB_USB=1269UCKFZTAM95OR REF_CLI_SERIAL=/dev/ttyACM0 DUT_DIAG_GPIO=2 DUT_DIAG_RAW_POWER_SETTING=44556688 DUT_DIAG_POWER=11 python3 ./tools/cp-caps/rcp_caps_test.py -d
+diag channel --------------------------------------------- OK
+diag channel 20 ------------------------------------------ OK
+diag power ----------------------------------------------- OK
+diag power 11 -------------------------------------------- OK
+diag radio sleep ----------------------------------------- OK
+diag radio receive --------------------------------------- OK
+diag radio state ----------------------------------------- OK
+diag repeat 10 64 ---------------------------------------- OK
+diag repeat stop ----------------------------------------- OK
+diag send 100 64 ----------------------------------------- OK
+diag stats ----------------------------------------------- OK
+diag stats clear ----------------------------------------- OK
+diag frame 00010203040506070809 -------------------------- NotSupported
+diag echo 0123456789 ------------------------------------- OK
+diag echo -n 10 ------------------------------------------ OK
+diag cw start -------------------------------------------- OK
+diag cw stop --------------------------------------------- OK
+diag stream start ---------------------------------------- OK
+diag stream stop ----------------------------------------- OK
+diag stats ----------------------------------------------- OK
+diag stats clear ----------------------------------------- OK
+diag rawpowersetting enable ------------------------------ NotSupported
+diag rawpowersetting 44556688 ---------------------------- NotSupported
+diag rawpowersetting ------------------------------------- NotSupported
+diag rawpowersetting disable ----------------------------- NotSupported
+diag powersettings --------------------------------------- NotSupported
+diag powersettings 20 ------------------------------------ NotSupported
+diag gpio mode 2 ----------------------------------------- NotSupported
+diag gpio mode 2 in -------------------------------------- NotSupported
+diag gpio mode 2 out ------------------------------------- NotSupported
+diag gpio get 2 ------------------------------------------ NotSupported
+diag gpio set 2 0 ---------------------------------------- NotSupported
+diag gpio set 2 1 ---------------------------------------- NotSupported
+```