Make query conditions section sticky and max size to 50vh

[marySalvi]

Closes #1219

• Adds Active query conditions section to the navigation prepend slot. This makes the section sticky while the rest is still scrollable
• Limits the height of this section to 50vh and overflow scrollable so that the use can always make additional selections

[marySalvi]

This works great! My only consideration here is moving the biosample results count and divider into the sticky section. Any thoughts on that change?

I fixed this. Definitely looks better with the divider too.