remove unneccessaries from pch to reduce size and fix storage quota issues in build

[burtonrodman]

significant reduction in size of PCH by removing unnecessary includes

[NickGerleman]

Lgtm assuming this still builds after removal.

[asklar]

this will reduce the pch size (known to be large) at the expense of slower builds (recompiling the same headers everywhere they are used), which for xaml headers can be significant.

[burtonrodman]

agreed. but if it doesn’t build at all because it generates a gig of pch and exceeds the build agent storage quota, then that perf gain is a detriment