High MLD fixes and LTV crash fixes

[x] ltv-Multi-channel 7_1_4 bitrate switching from 24.4 kbps to 256 kbps, 48kHz in, 32kHz out, STEREO out, FER at 5% crash fix
[x] [stv-Multi-channel 5_1 at 24.4 kbps, 48kHz in, 48kHz out, STEREO out] MLD fix
[x] ltv-Multi-channel 7_1_4 bitrate switching from 13.2 kbps to 512 kbps, 48kHz in, 48kHz out, HOA3 out crash fix

Pipeline results:

• EVS 26.444 BE test passes.
• decoder pytests:
  MLD scores:
  Original inputs: 562 failed, 374 skipped
  MLD > 10: 34
  MLD > 5 : 84
  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: 15
  MLD > 5 : 47
  MLD < 5 : 500
  +10dB inputs: 562 tests:
  MLD > 10: 44
  MLD > 5 : 128
  MLD < 5 : 390
  -10dB inputs: 562 tests:
  MLD > 10: 5
  MLD > 5 : 21
  MLD < 5 : 536