[Performance] Improve/address file searching especially for large workspaces

[SydneyhSmith]

There are significant performance impacts on projects with a large number of files in a workspace because of the way and frequency PSES searches through all of the files in a workspace

[fflaten]

Fixed by #1917, @SeeminglyScience? Should only read files once + on change now.
And we can't affect VSCode-searching in general, right?