pczt: Define the structure and semantics of the PCZT format #6108

Job	Run time
Latest build on ubuntu-latest	2m 7s
Test on Linux	6m 30s
Latest build on windows-latest	3m 56s
Test Orchard on Linux	2m 34s
Latest build on macOS-latest	1m 50s
Check ZFuture build on Linux	32s
Test NU7 on Linux	6m 27s
Check ZFuture build on macOS	42s
Test on macOS	9m 33s
Check ZFuture build on Windows	3m 10s
Test Orchard on macOS	4m 14s
Test on Windows	12m 39s
Build target wasm32-wasi	57s
Clippy (MSRV)	1m 20s
Test Orchard on Windows	4m 12s
Test NU7 on Windows	14m 53s
Bitrot check	1m 36s
Clippy (beta)	15s
Code coverage	1h 31m 57s
Intra-doc links	2m 12s
Rustfmt	13s
protobuf consistency	1m 2s
UUID validity	4s
Required status checks have passed	1s
	2h 52m 56s

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