SpendBundle members

[arvidn]

This PR is best reviewed one commit at a time.

The core of this patch is adding the following member functions to the SpendBundle type:

    @staticmethod
    def aggregate(sbs: List[SpendBundle]) -> SpendBundle: ...
    def name(self) -> bytes32: ...
    def removals(self) -> List[Coin]: ...
    def additions(self) -> List[Coin]: ...
    def debug(self) -> None: ...

By far the most complex one is additions(), which actually runs the puzzles in the spend bundle, and pulls out the CREATE_COIN conditions to return the coins being created by the spend bundle.

Most of the additional code are tests, a fuzzer and an extension to the corpus generation tool to pull out spend bundles from the block chain database.

[coveralls-official]

Pull Request Test Coverage Report for Build 7333749758

• 156 of 201 (77.61%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.1%) to 86.023%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
chia-protocol/src/program.rs	29	33	87.88%
chia-tools/src/visit_spends.rs	0	5	0.0%
chia-protocol/src/spend_bundle.rs	127	163	77.91%

Totals
Change from base Build 7333029126:	-0.1%
Covered Lines:	11035
Relevant Lines:	12828

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💛 - Coveralls

[Rigidity]

looks good