Add support pipeline test extra flags

[endast]

What

Updates the test-pipeline to add support for extra snakemake flags.

You can now pass extra flags to the snakemake cmd using the pipeline_extra_flags parameter.

jobs:
  # Training Pipeline
  Smoke-RunTraining:
    uses: ./.github/workflows/run-pipeline.yml
    with:
      pipeline_file: ./pipelines/run_training.snakefile
      environment_file: ./deeprvat_env_no_gpu.yml
      pipeline_extra_flags: --verbose # Example of adding the verbose flag