Fix token instance QR code data when api_path is different from path

[vbaranov]

Motivation

Continuation of #3016

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 428256c4-e3f9-49f4-bdc1-d03c3a3b57e3

• 6 of 22 (27.27%) changed or added relevant lines in 2 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.1%) to 75.266%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
apps/block_scout_web/lib/block_scout_web/views/api_docs_view.ex	6	8	75.0%
apps/block_scout_web/lib/block_scout_web/views/tokens/instance/overview_view.ex	0	14	0.0%

Files with Coverage Reduction	New Missed Lines	%
apps/block_scout_web/lib/block_scout_web/controllers/address_transaction_controller.ex	1	65.0%

Totals
Change from base Build aba031ac-f8d2-4a4b-a62c-c9aacd9cd259:	-0.1%
Covered Lines:	5438
Relevant Lines:	7225

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💛 - Coveralls