6) Complete merging the decoder

Created by: abukharmeh

Finishes merging the decoder.

Not much changes in this PR apart from removing couple of redundant checks legacy of the old decoder. Initially, it was like this as I was running formal while moving every quadrant.

When reviewing this PR, I advise to look at it with ignore white space changes option on, as a a lot of the indentations where changed, but not much code.