Otherwise we can get into race conditions where we run a request before the index has actually been updated.
While at it, also add logging when IndexStoreDB has been updated.
rdar://126635046
Add `.swift-format` to the repo and format the repo with `swift-format`.
This commit does not add any automation to enforce formatting of sourcekit-lsp in CI. The goal of this commit is to get the majority of source changes out of the way so that the diff of actually enforcing formatting will have fewer changes or conflicts.
