vsce: implement search UI
Created by: tjkandala
Implement search UI in the VS Code extension.
Part of post-release cleanup tracked in #32674.
NOTE: Only need review on changes outside of client/vscode
. We made this decision shortly after releasing v1 of the new VS Code extension. We do not have an automated release process yet, and the core codebase is mostly unaffected. The new GitHub Pull Request File Tree should help with this review :).
Test plan
-
Web app should be unchanged functionally. Automated tests are passing. Manually tested search to ensure that the core flow still works.
-
VS Code extension has been released to users based on this branch multiple times. It is in a working state, confirmed through manual testing before each release. We have added a smoke test to ensure the extension compiles and loads (homepage), and we are in the process of implementing request interception in order to add integration tests.