[SM6.10] Use consistent naming for ComponentType parameters

[hekota]

Follow up from #8299:

"I found that inconsistent naming for typename ...Ty vs. ComponentEnum ...Ty made this harder to read and review.

Matrix uses ComponentEnum MatrixDT, which helps, but DT isn't a convention used elsewhere, nor does it match the naming ComponentType which has a long history in HLSL and would better match the ComponentEnum naming.

Could we standardize on naming things with CT when referring to a ComponentType specified by the ComponentEnum and Ty when referring to an actual native type?"

Originally posted by @tex3d in #8299 (review)