Fixes #117084

Fixes #116589

* Tests: avoid creating real editors (fix #115230)

* tests - bring back file editor input factory test

* tests cleanup

* more cleanup

add TernarySearchTree#forUri2 which allow correct path casing handling, https://github.com/microsoft/vscode/issues/110241

This allows to use the ResourceMap with case insensitive path logic etc

This reverts commit fb196011.

That commit causes a hard freeze in tasks. Reverting for now.

fyi @dbaeumer

fyi @bpasero

make TenarySearchTree have generic key and value, implement for URI, touches on https://github.com/microsoft/vscode/issues/93368

* Enable strict null checking for String test

* Enable strict null checking for Uri test

* Enable strict null checking for Map test

* Enable strict null checking for node/pfs test

* Enable strict null checking for node/glob test

We are ok with tests throwing on undefined access, so use the not null assertion heavily here

We set alwaysStrict so this directive is not needed

Standardizing syntax and discouraging use of `this` inside tests