Resolve "Add levels to 26.252 BE conformance scripts"
Reason why this change is needed
- Level-based conformance is missing in the conformance test
Description of the change
- Integrate level-based option into conformance test (ENC and DEC). Level-based conformance is defined in 3GPP TS 26.252.
Affected operating points
- ENC and DEC tests (LEVEL1 and LEVE3)
Related to #1422