Resolve "Arbitrary quantities in ES"

Closes #1097 (closed)

This is the implementation so far:

• all quantities below the data section that are string, float, int, date, or enums and have a scalar shape are add to and indexed in metadata.searchable_quantities
• There is a special filter menu for those "custom" quantities.
• In this menu you can create a long AND of criteria. This could be extended to support ORs and NOTs.
• For each criteria, you can select from all the available quantities found in NOMAD's data. Currently this is a select and should be extended into an autocomplete. The quantities are select by their "path", i.e. position in the data
• For each criteria there might be operators (<,>, >=, <=) to select from. Operators depend on the selected quantity and its type.
• For each criteria there is a value to enter. We reuse the edit quantity components here. It might look different based on the quantity type.