lfExtModifier::ModifyColor_DeVignetting_PA_SSE2: reduce code duplication
This de-duplicates almost half of the lines in that file.
lfExtModifier::ModifyColor_DeVignetting_PA_*SSE2*: redefine using templates

Explicit (full) template specialization must be declared before the
first use, so we need to #include "" source,
we can no compile it separately.
[WIP] lfExtModifier::ModifyColor_DeVignetting_PA_: add SSE for lf_f32