High MLD fixes for LTV, HP20 filter optimization, float code cleanup

[x] HP20 filter recoding for WMOPS optimization
[x] Fix for LTV High MLD due to old_out in ivas_core_dec, decoder_tcx_ivas_fx
[x] Apa-Exec float code cleanup
[x] Fix for high mld issue for the case - [ltv-stereo at 13.2 kbps, 32kHz in, 32kHz out, DTX on]

• EVS 26.444 BE test passes.
• decoder pytests:
  MLD scores:
  Original inputs: 562 failed, 374 skipped
  MLD > 10: 9
  MLD > 5 : 13
  MLD < 5 : 540
  +10dB inputs: 562 failed, 374 skipped
  MLD > 10: 30
  MLD > 5 : 88
  MLD < 5 : 443
  -10dB inputs: 562 failed, 374 skipped
  MLD > 10: 1
  MLD > 5 : 14
  MLD < 5 : 547
• encoder pytests results:
  MLD scores:
  Original inputs: 562 tests:
  MLD > 10: 18
  MLD > 5 : 67
  MLD < 5 : 477
  +10dB inputs: 562 tests:
  MLD > 10: 69
  MLD > 5 : 122
  MLD < 5 : 371
  -10dB inputs: 562 tests:
  MLD > 10: 5
  MLD > 5 : 24
  MLD < 5 : 533