[non-BE][split-non-BE] Fix issue 1380 by changing panning gains for OMASA encoding to use look-up tables

• Related issues: #1380 (closed)
• Requested reviewers: @tyagiri @tamarapu

Reason why this change is needed

• Larger differences were noticed for OMASA encoding between Release and Debug (-O2 vs O0). This was pinpointed to panning gain computation.

Description of the change

• This picks the approach using look-up table from BASOP and implements it in float.

Affected operating points

• Bitstream changes for OMASA operation points where downmix is created.
• Same function is used for OMASA EXT output and in object editing within ParamBin so these may have non-BE output as well.