Perform nav bar computation in two passes

[CyrusNajmabadi]

Fixes https://devdiv.visualstudio.com/DevDiv/_workitems/edit/2065682

This follows the same change made in taggers back in #72878.

The idea is fairly simple. When computing nav bar items, we always first try a simple and quick pass using frozen-partial semantics. This allows the nav bars to be reasonably up to date with whatever the user jsut types, as well as with the last contents of SG documents and skeleton references.

As long as new changes are coming in, we keep performing those cheap computation passes.

When a cheap computation pass finishes, we then enqueue a request to do one final expensive pass that will actually update hte navbars with non-frozen data. Thus, ensuring that we always finally get into a final, correct, state. That expensive pass will be pre-empted by more cheap requests that come in. But we'll always eventually run that expensive/correct pass as the final thing we do.

[CyrusNajmabadi]

mirrors what we do in tagging.

[CyrusNajmabadi]

mirrors the same logic in tagging.

[CyrusNajmabadi]

same pattern as tagging (including nameing).

[CyrusNajmabadi]

@jasonmalinowski @sharwell @ToddGrun ptal. This impacts a large partner.

[jasonmalinowski]

It feels like there should be an easier way to do this. If a feature was added to the queue to just say "and run this once there are no batches left" it might be easier? I think? Either way since this pattern is established, no reason to try to delay this here.

[CyrusNajmabadi]

It feels like there should be an easier way to do this. If a feature was added to the queue to just say "and run this once there are no batches left" it might be easier?

I'm waiting for the 3rd feature to need this. At that point, i'll wrap up in a helper (or make part of the queue itself :)).