Show room suggestions

[ChristophWurst]

Extracted from #3184

Requires #3543

[ChristophWurst]

Fresh ideas from last week's call with @nimishavijay and @st3iny

• Put the search input/multiselect on top, above the capacity and room type
• Show room suggestions underneath all the inputs, with a dedicated heading *Suggestions
  • If possible/applicable use the number of current participants as minimum capacity
  • Only suggest rooms, not resources
  • Drop the subline that currently says "Checking availability"
• As soon as at least one room or resource is selected, don't show any suggestions anymore

[nimishavijay]

More suggestions:

• don't show minimum capacity and room type fields by default, use a toggle like a filter icon
• OR use smaller fields (50% of sidebar width) so that both the fields fit in one line
• not entirely convinced about finding out room availability only after saving, we can discuss with @jancborchardt as well later and fine tune a nicer workaround
• selected rooms can have a trash icon on the right side to remove, suggested available rooms can have a plus icon to add (this is the best way of differentiating between selected and suggested rooms that I can think of, but I'm not fully convinced either, it might be a lot to cram into one list item)

[jancborchardt]

not entirely convinced about finding out room availability only after saving, we can discuss with @jancborchardt as well later and fine tune a nicer workaround

Can you expand on that @st3iny @ChristophWurst? That would sound indeed a bit like a chore then to find an actually available room. :)

[ChristophWurst]

We'll have to test what's possible or not.