chore: cleanup, make value & block stack fixed size #423

Job	Run time
Build wasm	2m 4s
Run tests on Linux x86 (nightly, no default features)	52s
Run tests on Linux arm64	1m 5s
Run tests on Linux armv7	1m 5s
Run tests on Linux x86 (stable)	50s
Run tests on macOS arm64 (Apple M1)	1m 5s
Run tests on Linux x86 (stable, no default features)	53s
Run tests on Linux x86 (nightly)	54s
	8m 48s

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