build: Minor tweaks and fixes

[twostars]

• Server.slnx: Ensure fetch-argparse depends on sync-submodules for the base lock

• ThirdParty.slnx: Add fetch-argparse here just to pre-emptively fetch it and not pollute build times. Ordinarily we add things here to have them excluded by CodeQL's scan, but this is header-only so it doesn't really matter here -- the only thing it's doing is inflating the build time associated with the server when it fetches the repo within the workflow.

• Restore parallel builds in workflows. I disabled this likely due to CPU starvation causing slower build times, but testing it now, it seems fine enough.

• Use Powershell for the Windows shell, not bash. bash can inherit paths that we don't intend.

• Only bother to apply the format check when we change source files that are checked (though we only roughly care about the extensions we actually use, not all that's checked).

• Tidy up N3ME's filters; this used to be one of the couple of tools that included N3Base source files directly. Only the empty folder remained - which has now been removed - and I shifted N3ME/* back up a level since there's no longer any need for separation.

• Ensure all tools add <N3Base/My_3DStruct.h> to their PCH for consistent PCH.

• Update server PCH to include common standard headers.

I avoid going too far with PCH, like adding N3UIBase.h for the client, even though most files reference it, simply because it starts to cause bad design issues (since it already exists in scope, we don't tend to think to include it, so anything that needs it and doesn't use PCH is confused because the original author never thought to include it directly).

It also just doesn't help that much more than it already is so it's generally not worth it.