In-database BIDS file information

[MaximeBICMTL]

This PR implements aces/Loris#11169 for the LORIS BIDS MRI and EEG importer. Code-wide, this PR improves the BIDS importer by refactoring BidsImportEnv into a more feature-complete BidsImporter class. However, the code for actual BIDS registration also complexifies the importer quite a bit, and simplifying it would require a large (but desirable) refactor of the BIDS importer (specifically create a common factorization for all BIDS file imports), which is outside of the scope of this PR. Integration tests are nonetheless improved in this PR to ensure that everything works as expected and continues to do so in the future.

BIDS importer design

• Rename BidsImportEnv to BidsImporter.
• BidsImporter is the central object for BIDS import, which contains:
  • Arguments passed to the BIDS importer.
  • State of the BIDS importer (successed/skipped/failed files).
  • Custom importers hooked to the LORIS BIDS importer.

Open design questions

• Should the BIDS dataset tables be used for the assembly BIDS (IMO yes).
• Store how each BIDS file was added to LORIS (importer/converter)?
• Add a script to generate BIDS dataset/files table from an already-imported BIDS dataset present on the file system?
• Many others!