[WIP] [ENH] implement bids-schema - part 1

[Remi-Gau]

Use the bids-schema from the specification repo to parse datasets.

• create function to load schema
• implement file parsing according to datatypes and modalities of the schema
• add functions to handle (for a given datatype):
  • entities
  • suffixes
  • extensions
• implement schema for parsing
  • anat
  • behavioral
  • ASL
  • dwi
  • func (fixes Missing or extra entities for func #104 and fixes Add support for cbv and phase sufixes for func files #103)
  • eeg
  • meg
  • ieeg
  • fmap

Issues

• Some suffixes are deprecated in BIDS 1.5 and not included in the schema (e.g FLASH), and therefore will be ignored by layout when parsing them.

• FIXED - Different types of "suffixes" allow for different set of entities for the same datatype (see below T1w do have a part entity and T1map does not, even though they are both anat). Relying on the schema when parsing leads to create concatenating structures that have different set of fields.

  {
    "suffixes": [
      "T1w",
    ],
    "entities": {
      "subject": "required",
      "session": "optional",
      "run": "optional",
      "acquisition": "optional",
      "ceagent": "optional",
      "reconstruction": "optional",
      "part": "optional"
    }
  },
  {
    "suffixes": [
      "T1map",
    ],
    "entities": {
      "subject": "required",
      "session": "optional",
      "run": "optional",
      "acquisition": "optional",
      "ceagent": "optional",
      "reconstruction": "optional"
    }
  },

[Remi-Gau]

Closing and reopening to have the dev branch as base.