refactor pre_validate_blocks_multiprocessing

[almogdepaz]

Purpose:

this pr simplifies pre_validate_blocks_multiprocessing by passing in the prev sub epoch block the sub slot iters and the difficulty, moving the calls to get_next_sub_slot_iters_and_difficulty outside

this means that the sub slot iters and difficulty are not validates inside pre_validate_blocks_multiprocessing so we still need to call get_next_sub_slot_iters_and_difficulty and compare once every epoch since that is the place in the code where we validate the sub slot iters and the difficulty using the timestamps from the chain

New Behavior:

no change to behavior

Testing Notes:

[github-actions]

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[github-actions]

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[github-actions]

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[github-actions]

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[arvidn]

without my proposed changes, the failure results in throwing an IndexError, rather than the expected INVALID_PREV_BLOCK_HASH error return value

[github-actions]

This pull request has conflicts, please resolve those before we can evaluate the pull request.

[github-actions]

Conflicts have been resolved. A maintainer will review the pull request shortly.

[arvidn]

you might want to rebase on top of refactor-get-block-generator in advance, to make sure it's a clean merge

[github-actions]

File	Coverage	Missing Lines
chia/consensus/blockchain.py	88.2%	lines 346, 349
chia/consensus/multiprocess_validation.py	97.4%	lines 233
chia/full_node/full_node.py	88.4%	lines 1422, 1443-1444, 1448, 1450, 1458-1462

Total	Missing	Coverage
227 lines	13 lines	94%

[coveralls-official]

Pull Request Test Coverage Report for Build 10743333697

Details

• 213 of 226 (94.25%) changed or added relevant lines in 17 files are covered.
• 29 unchanged lines in 8 files lost coverage.
• Overall coverage decreased (-0.02%) to 90.908%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
chia/consensus/blockchain.py	14	15	93.33%
chia/consensus/multiprocess_validation.py	37	39	94.87%
chia/full_node/full_node.py	76	86	88.37%

Files with Coverage Reduction	New Missed Lines	%
chia/data_layer/data_store.py	1	94.58%
chia/consensus/multiprocess_validation.py	1	94.07%
chia/rpc/rpc_server.py	1	89.14%
chia/daemon/client.py	1	73.94%
chia/full_node/weight_proof.py	4	90.51%
chia/server/server.py	4	82.21%
chia/full_node/full_node.py	8	86.16%
chia/server/node_discovery.py	9	79.43%

Totals
Change from base Build 10742893367:	-0.02%
Covered Lines:	101582
Relevant Lines:	111707

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💛 - Coveralls

[pmaslana]

@arvidn @almogdepaz Is it ok to remove the coverage_diff label and merge?