Draft: [CI] test-be-release-pre-test job

• Related issues: #739
• Requested reviewers: @pajunen, @pihlajakuja, @kiene

Reason why this change is needed

• Adds be-to-release-pre-test manual pipeline job.
  • runs exhaustive encoder testcases (excluding bitrate sw) with longer test vectors.
  • bitstream comparison between two selected commits.

Description of the change

• An example on how to trigger the manual job below.
• 

Affected operating points

• Describe here as well as possible what operating points are affected and how
• In minimum, there should be a status for bitstream compatibility and output bit exactness
• For bitstream compatibility, the following levels are helpful for describing encoder
  1. Produced bitstream is BE compared to previous state.
  2. Produced bitstream is non-BE but it is fully backwards compatible for decoding. Decoded output may differ.
  3. Produced bitstream is non-BC. Old decoder cannot decode the produced bitstream correctly.
• For output difference, use BE or non-BE. Additionally, amount of difference can be presented.