improve(E2E): wire quickpick titles into Quickpick call sites

[Dave Shoup (shouples)]

Summary of Changes

Note

Stacked on top of #3442, which adds the titlePattern capability to the Quickpick page object. Review and merge that one first; this PR's diff is only the call-site wiring.

Previously, an E2E step could interact with the wrong quickpick (for example, a transient "Loading Kafka clusters..." placeholder) before the real one appeared, because nothing verified which quickpick was on screen. This PR closes that gap by wiring the titlePattern argument added in #3442 into the ~26 existing new Quickpick(...) call sites, so each step now asserts on the exact title the quickpick renders before interacting with it.

Titles were traced to their source literals in src/quickpicks/ and src/commands/ (e.g. Select a Kafka cluster, Choose a schema type, Upload Flink Artifact). The two schema-kind pickers use a dynamic title (Producing to ${topic.name}: Select Schema Kind(s)...), so those pass a RegExp instead of a string. Call sites with no title (project-template picker, connection-type picker) or backed by a VS Code built-in (command palette, language-mode picker) were left untitled on purpose.

Click-testing instructions

Not applicable (E2E test infrastructure with no user-facing behavior). This should be validated by a full E2E run on CI.

Optional: Any additional details or context that should be provided?

• npx gulp check, ESLint, and Prettier pass on the changed files. As with the parent PR, the full Playwright E2E suite needs Docker, the sidecar, and Electron, so it was not run locally; a CI E2E run is the real verification that each wired title resolves.
• Scoped intentionally to Quickpick. Deliberately out of scope: wiring titlePattern into the adjacent InputBox call sites. This PR applies it broadly to Quickpicks (unlike InputBox, which uses it in only 1 call site) because multiple quickpicks can be visible or transitioning at once.

Relates to #2740

Pull request checklist

Please check if your PR fulfills the following (if applicable):

Tests

• Added new
• Updated existing
• Deleted existing

Release notes

• Does anything in this PR need to be mentioned in the user-facing CHANGELOG?

[sonarqube-confluent]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarQube