Adding EEG Benchmark

[mravanelli]

With this PR, we upload the SpeechBrain-MOABB EEG Benchmark. Before finalizing a few things are missing:

• [x] Add models in dropbox
• [x] Update tables with the latest results
• [x] Restore orion flags in hparam files
• [x] Upload all hparam files
• [x] Add max_sub_opt for hparam optimization.
• [x] add output file examples in Readme
• [x] add recipe tests
• [x] test on different machines

[mravanelli]

Great job! This is now ready to be merged and be officially part of SpeechBrain!