getsourcecode API endpoint: show data for unverified contract from verified contract with the same bytecode

[vbaranov]

Resolves #3632

Motivation

Display ABI and other data of verified contract at getsourcecode API endpoint for the contract, which is not verified but has the same bytecode.

Checklist for your Pull Request (PR)

• I added an entry to CHANGELOG.md with this PR
• If I added new functionality, I added tests covering it.
• If I fixed a bug, I added a regression test to prevent the bug from silently reappearing again.
• I checked whether I should update the docs and did so by submitting a PR to https://github.com/blockscout/docs
• If I added/changed/removed ENV var, I submitted a PR to https://github.com/blockscout/docs to update the list of env vars at https://github.com/blockscout/docs/blob/master/for-developers/information-and-settings/env-variables.md and I updated the version to master in the Version column. Changes will be reflected in this table: https://docs.blockscout.com/for-developers/information-and-settings/env-variables.
• If I add new indices into DB, I checked, that they are not redundant with PGHero or other tools

[coveralls]

Pull Request Test Coverage Report for Build 4a597efdb81b3b6a46e3c51aefe06b62994e5522-PR-3637

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 3 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-2.3%) to 64.585%

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Files with Coverage Reduction	New Missed Lines	%
test/block_scout_web/features/pages/chain_page.ex	1	90.0%
lib/block_scout_web/controllers/chain/market_history_chart_controller.ex	2	71.43%

Totals
Change from base Build 71d3e40e7bf3c16c6fff4cfdbb3c625b15cdd9e9:	-2.3%
Covered Lines:	2099
Relevant Lines:	3250

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💛 - Coveralls