[d3d8/9] Properly handle resource priority

[WinterSnowfall]

The d3d8/9 behavior with regards to resource priorities is pretty straight forward:

• D3D8/9Resource::SetPriority() only works for resources in D3DPOOL_MANAGED
• everything else returns 0 above and on D3D8/9Resource::GetPriority() (esentially the value used above is ignored)

d3d9Ex, in its eternal wisdom decided to switch this up and:

• D3D9Resource::SetPriority() only works for resources in D3DPOOL_DEFAULT
• everything else returns 0 above and on D3D9Resource::GetPriority(), including anything in D3DPOOL_MANAGED
• there's a list of constants you can use with SetPriority(), but they're not mandatory and apps can basically set pretty much anything they want

I'm aware our backend doesn't use the priority for anything really, but I guess some games might depend on it for their own internal stuff. Oh, and Wine has a d3d8/9 test for it that fails without this PR, which annoyed me.

So this is now pretty much native behavior, as annoying as it was to get everything in place within templateing nightmares and whatnot.

Still need to double check if the tests are happy, and I'll undraft after I've confirmed.

[WinterSnowfall]

Ended up having to fix some odd crashes with the x64 builds of the Wine device tests (which to be fair I haven't checked in like ages, since I didn't expect any foul play vs x32).

I've confirmed the priority behavior is now in line with expectations.

[K0bin]

A few nits. Please tell me if you disagree with any of them or if it gets too nit-picky.