Tweak the page title for code intelligence settings.

Created by: olafurpg

Previously, the page title was "404 not found" while the code intelligence settings UI was loading in the browser. The title would then get updated to the correct title after the SPA finished loading. This commit adds a server-side route handler so that the title is "Code intelligence" instead of "404 not found" while the page is loading.

We also remove the "Precise" prefix from the title in code intel settings pages. The "Precise" prefix is technically accurate, but it's inconsistent with the "Code Intelligence" button that users click to view those settings. "Precise code intelligence" is also so long that it's usually truncated by the browser so that you can't see the config/uploads/auto-index suffix in the subpages.