Improve appearance of filters

[krabina]

Some ideas on how to improve the visual appearance of the filters:

I suggest to add the option "format" to the filter definitions:

{{#drilldowninfo:
 filters=Institution (property=Institution,format=collapsed),
}}

that would collapse the filter. If you use many filters, having them all uncollapsed takes away too much space.

Format could also be repeated for other options, e.g.

{{#drilldowninfo:
 filters=Institution (property=Institution,format=collapsed,format=block),
}}

could not display "Institution", the select field and the "Search" button all in separate lines, but in one line.

{{#drilldowninfo:
 filters=Institution (property=Institution,format=slider),
}}

format = slider could display a slider instead of from and two-dates for a date filter.