Optim: isTexelCoordNormalizable<>()

• New isTexelCoordNormalizable<>() function, an optimization of normalizeTexelCoord<>() which only returns the boolean "valid" state without doing any of the normalization.
      » Always returns true for OutsideOfQuadUVWrap and OutsideOfQuadUVClamp; ideally these would be template-optimized out.
      • In use in surfaceSTToTexelUV_bilinearQuad<>() for the U coord; we only need to know if an early-out should be taken here.