Display implementation address at read/write proxy tabs

[vbaranov]

Resolves #3162

Motivation

Implementation address is not displayed at read/write proxy tabs

Changelog

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 dac3b6d1-f434-4fc5-99e7-e4dd25d81ec5

• 2 of 2 (100.0%) changed or added relevant lines in 1 file are covered.
• 9 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.1%) to 74.374%

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Files with Coverage Reduction	New Missed Lines	%
apps/block_scout_web/lib/block_scout_web/controllers/chain/market_history_chart_controller.ex	2	71.43%
apps/indexer/lib/indexer/block/catchup/bound_interval_supervisor.ex	3	85.19%
apps/indexer/lib/indexer/block/catchup/fetcher.ex	4	69.88%

Totals
Change from base Build be954bf9-bf72-46e6-a1fa-db3b81cc8979:	-0.1%
Covered Lines:	5967
Relevant Lines:	8023

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💛 - Coveralls