Fix searchform collapse behaviour

[crftwrk]

This PR improves/fixes the searchform collapse behaviour.

Before

https://bootscore.me

• Click on search toggler opens collapse and focusses the searchform
• If searchform loses focos, collapse hide

This works fine if bootScore/Woo searchorm or a a completely different widget is used in this position. In #312, a third party searchform is used. The result: On toggler click, searchform collapse opens but form gets not focussed. Because there is no focus, collapse close by itself.

After

Closing collapse is now decoupled from searchform focus. Snippet checks if a click is outside #collapse-searchand closes collapse then.

• Click on search toggler opens collapse and focusses the searchform
• If click is outside #collapse-search, collapse hide

Test

https://dev.bootscore.me/

• Click search-toggler in the navbar
• Click inside #collapse-search just 1px left or right next to the search´form - searchform stays open
• Click somewhere outside - collapse hides

Closes #312

[justinkruit]

I know having a click check on every body click could get heavy for a browser, but I don't notice a performance hit on this, so this should alright.

[crftwrk]

Want to merge quickly? I‘m not in front of my machine right now.