trace: Add functionality to parse DMA trace

[colluca]

• gen_trace.py: output the trace to a file provided on the command-line rather than stdout
• gen_trace.py: add functionality to parse DMA traces, calculate DMA performance metrics and output to file
• target: update commands invoking the tracer scripts to align them with the previous changes
• util/bench: update benchmarking scripts to process both hart and DMA traces. Includes:
  • Major change from CSV to JSON format in intermediate output files
  • Add mkdocstrings documentation for benchmarking scripts
  • Following test-driven development approach, add pytest unit tests to CI
• Solve issues described in (Not a PR to main): Improve DMA tracer handling of 1d requests after 2d requests and scale units correctly #69
• Rebase onto main, including iDMA change
• Update tutorial [POSTPONED]
• Wait for release of Restore tracing in Snitch DMA iDMA#52 [POSTPONED]: instead temporarily build sources locally, revert this later