Standardize token name definition, if name is empty

[vbaranov]

Closes #2536

Motivation

Standardize token name definition if there is no name:
"0x" + "left::binary-size(6)" + "-" + "right::binary-size(6)"

An example: 0x8a55f3-b3b9a5

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 5a4e912adeafd40cc6a4153257393d8753549ffa-PR-3431

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 9 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+2.4%) to 67.586%

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Files with Coverage Reduction	New Missed Lines	%
lib/block_scout_web/views/address_view.ex	9	81.61%

Totals
Change from base Build f92bab912b2ee45260990a6781a8111d381cd34f:	2.4%
Covered Lines:	2058
Relevant Lines:	3045

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💛 - Coveralls