[FEA] Investigate mixing transforms and operators

[cliffburdick]

Right now to do an FFT convolution at least three separate lines must be written:

1. FFT input
2. element-wise multiply the output
3. IFFT the multiplied results

This limitation is due to how we treat transforms and operators differently. This issue is to investigate mixing the two, which has many benefits, including saving temporary variables, more readable code, and more chances for optimizations in the parsing.