Add global analysis driver pool to protect usages

[jakemac53]

Fixes #3312

If the driver is used in between calls to changeFile and before applyPendingChanges completes, then you can get InconsistentAnalysisErrors. This change ensures we won't do that through a new single resource pool shared by all users of the driver.

• Guard all accesses to the driver and session with the new resource.
  • During the resolve, this only grabs the resource once it is fully ready for all of the changeFile calls and subsequent call to applyPendingFileChanges. This prevents deadlocks compared to a global resolution pool, which may call out to package:build apis which can deadlock.
  • This shouldn't cause significant slowdown, most of the code using the pool has a fixed number of async actions it waits on, and none of those actions might need to wait on a build step to complete (they are all async calls to analyzer apis, not build apis).
• Keeps in place the per action resolve pool, still needed for managing updates to _entryPoints.
• Temporarily overrides all packages to run with this version of build_resolvers, will revert that commit before landing

[natebosch]

Can we expand the commit message with 2 things:

• More details about why we need to guard access to reads from the driver.
• A rough sketch of the way the code is changing - in particular the nested function argument used to lock only part of the work.

[jakemac53]

Can we expand the commit message with 2 things:

How does the updated text look?

[natebosch]

How does the updated text look?

Looks great to me. Thanks!