add blocks cache

[ayrat555]

fixes #2034

Changelog

• add blocks cache

[coveralls]

Pull Request Test Coverage Report for Build 77e3d03d-e710-4d06-90e3-4c1e87b5e8dd

• 38 of 41 (92.68%) changed or added relevant lines in 4 files are covered.
• 7 unchanged lines in 4 files lost coverage.
• Overall coverage decreased (-0.04%) to 80.96%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
apps/explorer/lib/explorer/chain.ex	7	8	87.5%
apps/explorer/lib/explorer/chain/blocks_cache.ex	28	30	93.33%

Files with Coverage Reduction	New Missed Lines	%
apps/block_scout_web/lib/block_scout_web/channels/exchange_rate_channel.ex	1	50.0%
apps/indexer/lib/indexer/fetcher/token.ex	1	78.57%
apps/indexer/lib/indexer/fetcher/token_balance.ex	2	87.1%
apps/indexer/lib/indexer/block/fetcher.ex	3	88.0%

Totals
Change from base Build 5bebd6bc-5a5f-4073-af4f-575a6b583ce1:	-0.04%
Covered Lines:	4860
Relevant Lines:	6003

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💛 - Coveralls

[vbaranov]

@ayrat555 it looks like cache is not invalidating. I see too many items on the first page. The screenshot is from stg server.

img

[vbaranov]

@ayrat555 cache invalidation still works incorrectly. I see ~ 600 blocks on the first page on stg.