Improve filtering in Compare dialogs

When trying to filter for a specific version or space, irrelevant versions or spaces are not hidden from the dropdown, instead only the text a user searches for is highlighted.
This makes the compare dialog hard to use if there are hundreds of spaces or versions created.

Note: When comparing page versions, the filtering works as expected.

Steps to reproduce:

1. Create a couple of versions with "real" names

2. Open the Compare Versions screen and search for a specific version name

Expected result:

• All other versions that do not match the version name are hidden in the dropdown.

Actual result:

• The search text is just highlighted, but no versions are hidden