Add Paired Single Move Tests

[Geotale]

Adds a new file for common float tests -- This will likely be used more in the future as well
Modifies two other test files which now use functions in the CommonFloat file
The location of frsqrte_expected might change because it's not exactly common? ^^;
Adds software implementation of mantissa truncation and rounding given the expected rounding mode
Both of these are for tests for float move instructions
These instructions include:
ps_merge, ps_mr, ps_neg, ps_abs, ps_nabs
ps_rsqrte is included to check for a similar quirk (it returns an f64)
Marked as a draft until I or someone else can test on hardware (so like. a few hours if I can get it working)

[JosJuice]

Your CommonFloat.h file is rather similar to Dolphin's Common/FloatUtils.h. I think it would be better to name the file FloatUtils.h, and to follow the approach of Dolphin's Common/FloatUtils.h where relevant (e.g. constexpr for constants instead of enums).

Will review the new hwtest in more detail once you've moved this out of draft state.