[non-BE] Resolve "Buggy stereo to FOA in JBM"

• Related issues: #1454
• Requested reviewers: @tamarapu

Reason why this change is needed

• Buggy stereo to FOA/HOA2/HOA3 in JBM

Description of the change

1. Fix stereo to FOA/HOA2/HOA3 in JBM + do the processing in dedicated function ivas_stereo2sba()
2. Simplifications + improvements within FIX_1419_MONO_STEREO_UMX to follow the rest of the framework
3. Do the EVS stereo panning in the renderer, under FIX_1435_MOVE_STEREO_PANNING, see #1435

Affected operating points

• non-BE for stereo to FOA/HOA2/HOA3 output in JBM