Block prevalidation port

[Rigidity]

This is an early WIP of porting block prevalidation to Rust. Only signature validation and some other scaffolding has been done so far.

[coveralls-official]

Pull Request Test Coverage Report for Build 8708877753

Details

• 11 of 406 (2.71%) changed or added relevant lines in 11 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-3.8%) to 81.547%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
crates/chia-consensus/src/gen/validation_error.rs	0	3	0.0%
crates/chia-consensus/src/gen/owned_conditions.rs	0	7	0.0%
crates/chia-consensus/src/block_prevalidation/pot_iterations.rs	0	11	0.0%
crates/chia-protocol/src/header_block.rs	0	11	0.0%
crates/chia-protocol/src/unfinished_header_block.rs	0	20	0.0%
crates/chia-consensus/src/block_prevalidation/unfinished_header_validation.rs	0	32	0.0%
crates/chia-consensus/src/block_prevalidation/finished_header_validation.rs	0	59	0.0%
crates/chia-consensus/src/block_prevalidation/npc.rs	0	65	0.0%
crates/chia-consensus/src/block_prevalidation/signature_validation.rs	0	82	0.0%
crates/chia-consensus/src/block_prevalidation.rs	0	105	0.0%

Totals
Change from base Build 8705995518:	-3.8%
Covered Lines:	11552
Relevant Lines:	14166

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💛 - Coveralls