Inline sourcegraph/code-intel-extensions
Created by: olafurpg
This commit ports all of the code from the repo sourcegraph/code-intel-extensions to replace our usage of webworker-based extensions. The "extension API" remains unchanged for codeintel actions like hover/definition/references, we can refactor that later if desirable.
Test plan
See the CI go green. This PR introduces minimal changes to our existing codebase, the goal of this PR is to inline the extensions code while keeping full fidelity with the old behavior (good and bad).
App preview:
Check out the client app preview documentation to learn more.