Subfunctions for dec_prm_tcx converted.

[x] Few functions from files dec_prm.c,bitstream_fx.c converted.

Testing:
[x] Decoder pytest: 568 failed, 1 passed, 381 skipped.
[x] MLD test: There is a deviation of more than MLD score of 5 for 11 files. For 8 files, issue has been resolved. The deviations are observed in Linux only and not in Windows. Debugging in progress.