Feature: Add an in-memory wallet backend framework #5089

Job	Run time
Bitrot check	1m 54s
Check ZFuture build on Linux	2m 38s
Latest build on ubuntu-latest	1m 31s
Check ZFuture build on macOS	5m 3s
Build target wasm32-wasi	1m 44s
Check ZFuture build on Windows	6m 54s
Clippy (MSRV)	1m 55s
Clippy (beta)	14s
Code coverage	18m 47s
Latest build on windows-latest	2m 54s
Intra-doc links	2m 13s
Latest build on macOS-latest	2m 24s
Rustfmt	27s
protobuf consistency	1m 33s
Test on Linux	8m 52s
UUID validity	7s
Test Orchard on Linux	6m 7s
Test NU6 on Linux	9m 0s
Test on macOS	26m 24s
Test Orchard on macOS	22m 22s
Test on Windows	13m 50s
Test Orchard on Windows	10m 41s
Test NU6 on Windows	14m 18s
	2h 41m 52s

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