Add levels to 26.252 BE conformance scripts
The conformance scripts should be updated with levels, such that conformance may be tested per level. The idea is to add test scripts for the Readme_IVAS_dec.txt and Readme_IVAS_enc.txt with specified levels.
The encoder can simply be split into levels depending on the encoding bit rate. For the decoder, the output format also needs to be considered somehow.
<!--- Below are labels that will be added but are not shown in description. This is a template to help fill them.
Add further information to the first row and remove and add labels as necessary.-->
task