Fix PSSA settings discovery + pick up changes to settings file

[rjmholt]

Fixes PowerShell/vscode-powershell#2489.

[bergmeister]

Some code comments but I can already confirm that this fixes the problem of not seeing PSSA warnings when there is no settings . Thanks for taking the time :-)

[bergmeister]

Code looks ok, I can re-test tomorrow again if the fix is still working after the last commits if you want to?

[rjmholt]

I can re-test tomorrow again if the fix is still working after the last commits if you want to?

Yes please.

I've tested (and stepped through in the debugger) all the scenarios I could think of:

• Default setting
• Empty string
• File not there
• File deleted

But could always use more eyes

[TylerLeonhardt]

We don't need the FileSystemWatcher if we still check if the file exists on every invoke. Refactor to not have file watcher.

[TylerLeonhardt]

LGTM

[bergmeister]

Re-tested with latest changes ✅