[Ref using main] Resolve "External renderer command-line"

• Related issues: #247 (closed)
• Requested reviewers: @sagnowski

Reason why this change is needed

• Harmonize command-line options names of external renderer with the decoder.

Description of the change

• Harmonize command-line options names of external renderer with the decoder and ensure only two variants (short and long) are always used and that the renderer short variant corresponds to the decoder variant.

Affected operating points

• All is BE.