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%
[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