[lesnik512]

#53 put named, linked or named, linked next to every Jira key on a row. Feedback: the labels weren't clear and made the column noisy. The words come from the report model, and the common case, where a merge request mentions its own key, doesn't need explaining.

Changes:

• A key the merge request or commit mentions looks like a plain key again, with or without a Jira link.
• A key the row carries only because the Jira issue links to the change gets a dashed underline, a link icon and via Jira. Hovering explains it, e.g. "Not mentioned in !54. SHOP-33 links to it in Jira."
• The viaNamed, viaLinked and viaTitle strings are replaced by viaJira and viaJiraTitle, in English and Russian.
• The demo links SHOP-33 to api !54, so the demo has one key added only by a Jira link. The tags and gaps shown don't change.
• docs/page.md describes the marker.

The report is unchanged; this only reads via.

Tests: test_demo_only_a_key_the_change_does_not_mention_is_marked_as_via_jira replaces the named/linked test. It checks that only SHOP-33 on !54 is marked, the hover text, and that a mentioned key has no marker. It failed before the change. just lint-ci, just test-ci and just test-smoke pass.