change(rpc): Update `getblock` RPC to more closely match zcashd #2158

Job	Run time
Install zebrad from lockfile without cache on ubuntu-latest	8m 45s
Test stable on ubuntu-latest	31m 32s
Check deny.toml bans	42s
Test beta on ubuntu-latest	31m 39s
Check Cargo.lock is up to date	1m 5s
Check deny.toml bans --features default-release-binaries	45s
Test stable on macos-latest	35m 58s
Check deny.toml bans --all-features	43s
Test stable on windows-latest	1h 0m 14s
Check for unused dependencies	7s
Test beta on windows-latest	1h 2m 3s
Check deny.toml sources	43s
Check deny.toml sources --features default-release-binaries	44s
Check deny.toml sources --all-features	43s
Open or update issues for OS integration failures	0s
	3h 55m 43s

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