Resolve "Render framesize in split rendering is unclear"

• Related issues: #1449
• Requested reviewers: @tyagiri

Reason why this change is needed

The renderer framesize (stored in the parameter st_ivas->hDecoderConfig->render_framesize) is confusing in the split rendering decoding:

1. When running the decoder with -fr X, the value render_framesize is always 20 ms regardless of the requested value X. This is set in IVAS_DEC_EnableSplitRendering().
   • Is it the intention that the option -fr X has no real meaning? Should it be then removed as the command-line parameter?
2. The value render_framesize is set to 5/10/20 ms when using the renderer configuration file. However, what is the intended processing for 10 ms around the limiter, specifically, shouldn't the if() condition contain the comparison against the 10MS size, too?

        if ( st_ivas->hDecoderConfig->render_framesize == IVAS_RENDER_FRAMESIZE_5MS )
        {
            ivas_limiter_dec( ... );
        }
        else
        {
            ivas_limiter_dec( ... );
        }

Description of the change

Add warning message informing the user that the renderer frame size has been changed. Simplify the logic around ivas_limiter_dec( ... );

Affected operating points

BE modification.