Fix token instance QR code data

[vbaranov]

Motivation

URL behind QR-code on token instance page leads to 404 page

Changelog

Add set_path parameter to blockscout_url method and pass false in case of constructing URL for QR-code

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 50cd323e-29fa-4aaf-86f5-2f5cce3cbf6b

• 3 of 5 (60.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.004%) to 75.371%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
apps/block_scout_web/lib/block_scout_web/views/tokens/instance/overview_view.ex	0	2	0.0%

Totals
Change from base Build f166d46a-d41e-459a-9fb5-430df5084406:	-0.004%
Covered Lines:	5432
Relevant Lines:	7207

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💛 - Coveralls