Encoder functions converted to fixed point

[x] Ported hq_generic_hf_encoding functions with minor modifications
[x] Extend lsf tools converted to fixed point
[x] FindChannelRatio and AdjustChannelRatios functions converted to fixed point
[x] Converted/updated few functions in ivas_stereo_td_analysis.c file
[x] Few functions in stereo_dft_enc path converted

Pipeline results:

• EVS 26.444 BE test passes.
• decoder pytests:
  MLD scores:
  Original inputs: 562 failed, 374 skipped
  MLD > 10: 33
  MLD > 5 : 85
  MLD < 5 : 444
  +10dB inputs: 562 failed, 374 skipped
  MLD > 10: 144
  MLD > 5 : 195
  MLD < 5 : 223
  -10dB inputs: 562 failed, 374 skipped
  MLD > 10: 8
  MLD > 5 : 40
  MLD < 5 : 514
• encoder pytests results:
  MLD scores:
  Original inputs: 562 tests:
  MLD > 10: 18
  MLD > 5 : 71
  MLD < 5 : 473
  +10dB inputs: 562 tests:
  MLD > 10: 66
  MLD > 5 : 124
  MLD < 5 : 372
  -10dB inputs: 562 tests:
  MLD > 10: 5
  MLD > 5 : 30
  MLD < 5 : 527