Add ability to filter available datasets in the "browse" panel

[ptaconet]

In addition to the current free-text search, add filters in the browse panel to select the correct dataset to visualise. These filters will allow the users to browse more efficiently the datasets available in the catalogue.

The filter elements should be the ones that define the permanent identifier of the datasets, i.e. :

• Tuna Atlas version: FAO, IRD, IOTC, ICCAT, IATTC, WCPFC, CCSBT
• variable to visualize: nominal catch, georeferenced catch, georeferenced efforts, georeferenced catch-at-size
• spatial extent: global, atlantic ocean, indian ocean, east pacific ocean, west pacific ocean, southern hemispheres
• spatial resolution: all resolutions, 5°, 1°
• level of correction: level 0, level 1, level 2