Document performance and minimum requirements for each operator

[geoffroy-noel-ddh]

Some newer operators may require a GPU or larger amount of RAM to work at an acceptable speed or at all. That's also dependent on operator parameters and input size (e.g. transcribe_speech_parakeet is a good example). Documenting baseline requirements and performance would help users. It would also help with testing more demanding operators in the right environments.

[geoffroy-noel-ddh]

One idea would be for the existing system tester to measure time and resource consumption for each operator in the sequence and return that in a table of json format.

Benefits:

• the tester works as a benchmark
• we can automatically get results for different environments
• we can also detect regressions in operator performances when they appear