Resolve "Fix forward vector for OTR REF VEC"

• Related issues: #954 (closed)
• Requested reviewers: @haeussler

Reason why this change is needed

• The IVAS forward vector definition is incorrect and needs to be fixed.

Description of the change

• Forward vector changed from [-1, 0, 0] to [1, 0, 0]
• Previous vector points in the wrong direction, this corrects it and updates the acoustic front vector too
• Only affects REF_VEC and REF_VEC_LEV modes for OTR

Affected operating points

• Binaural output with head and orientation tracking with modes REF_VEC and REF_VEC_LEV
• All is BE

Related to #954 (closed)