Generic improvements and optimisations for CI pipeline

This issue collects various tasks that have been thought out and can improve CI pipeline. Tasks can be split to separate issues linked to here if necessary.

• Apply needs relations to jobs to improve parallelism
• Study if we could apply changes keyword to run pipeline only on changes which can affect the build or test results
• Add a short report of useful information at the beginning of the pipeline. This could include at least branch commit SHA and merge target SHA.
• Make MR pipelines interruptible (cancel running pipeline on new push)?