Fix for ESP32 breaking changes

The latest ESP32 support appears to have broken things with a warning/error and problem using the std::string class. This is a simple fix to get it running again.

Added support for UNO R4 WiFi and additional printers

This release adds several improvements contributed by other developers (e.g. cleanup of supported printer list). I also added specific support for the Arduino UNO R4 WiFi board. It has less RAM and I corrected the font data to be const so as not to use up RAM space. I also added support for a new named printer which behaves the same as the "MTP-2" type.

Barcode support

This release adds support for printing 1D and 2D barcodes on supported printers. Only the MTP2 (PT210) and MTP3 support this feature (so far). This release also fixes a problem with paper feed on the cat printer.

Added M5StickC-Plus example

This release adds the Telegram bot shopping sketch for the M5StickC-Plus. Useful status info is displayed on the LCD and the main button (A) can be used to initiate printing on a nearby BLE thermal printer.

Telegram bot example

This release adds a sample sketch which implements a Telegram bot shopping list. This allows multiple users to collaboratively create a shopping list and then print it on a supported BLE thermal printer. This release also fixes a problem with the font boundaries when printing Adafruit_GFX proportional fonts.

Added support for multiple brands of thermal printer

This release is a major overhaul of both the BLE communication code and the printer output stage. I've added support for 3 more thermal printers and a few new functions for drawing Adafruit_GFX fonts without needing a graphics backing buffer.

Fix typo preventing Nano 33 BLE from working

In a previous update I had redone the #ifdef's to separate the Arduino, ESP32 and Adafruit BLE APIs and in the process, i accidentally broke the Nano33 from working. This release corrects that bug.

writeWithResponse again...

Somehow the latest version of the ESP32 BLE support broke the write (withoutresponse) logic of this library. I changed the code to default to write "withResponse" now. It's slower, but it restored everything to working. I also added a new function to change this if you want to try your luck.

Adafruit Bluefruit support

This release adds support for Adafruit Bluefruit nRF52 boards. Now all popular BLE devices - ESP32, Arduino Nano33 / Portenta, and finally Adafruit native code on nRF52xxx.

Fixed ESP32 regression bug

After I converted it to run on the Nano 33, I broke the scan matching on the ESP32. This fix recovers that and protects against name mismatches. BLE names sometimes have trailing spaces. If I just did a simple strcmp() with the name you're searching for, it won't always match. I switched to using the given name as a fixed length memory compare and this should prevent problems in the future.