Exclude balance percentage calculation for burn address on accounts page

[vbaranov]

Fixes #3103

Motivation

#3103 (comment)

Changelog

Doesn't show balance percentage to market cap for burn address.

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 7f75aa3b-d0de-4a91-887c-5f99963dd11f

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 7 unchanged lines in 2 files lost coverage.
• Overall coverage remained the same at 75.086%

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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/explorer/lib/explorer/chain_spec/genesis_data.ex	5	9.09%

Totals
Change from base Build acb221d3-f43d-4c53-bb95-61ce16abad7c:	0.0%
Covered Lines:	5705
Relevant Lines:	7598

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💛 - Coveralls