expose bytes32 as the right type, from chia-blockchain

[arvidn]

Now that we have the infrastructure to have these custom conversions, we might as well do it for bytes32 as well.
This addresses a lot of risks when using these types in chia-blockchain, as we don't have test coverage for all places we print bytes32 objects for instance.

[coveralls-official]

Pull Request Test Coverage Report for Build 7900076240

Details

• -1 of 5 (80.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.003%) to 84.932%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
chia-protocol/src/bytes.rs	4	5	80.0%

Totals
Change from base Build 7877262781:	-0.003%
Covered Lines:	11301
Relevant Lines:	13306

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💛 - Coveralls