[BUG] Can't remove "Search Sub-Collections".

[rosiel]

Reproduce this issue

• Use the default starter site or otherwise set up a view to have a "member of" and "descendant of" contextual filter. If setting it up from scratch, go into the block configuration for the Advanced Search (for block) block and select the appropriate contextual filter under the "Context filter" option.
• Realize that you have shallow collections so you don't need "Search sub-collections".
• Attempt to un-select the "Context Filter" option within the Block configuration for the Search [this collection] block. Find that you can't unselect anything. Ctrl-click doesn't work. "Search sub-collections" checkbox persists.
• Remove the "Member of" (or "Descendant of") contextual filter. Now you only have one contextual filter. The "Search sub-collections" checkbox persists.
• Go back into the block configuration and find that even though you only have one contextual filter available, it's selected and greyed out (can't un-select). The "Search sub-collections" checkbox persists.
• Go into Devel > Config Editor. Remember that the last time you tried to null out an array that was no longer accessible in the GUI, you broke the site and we had to restore from backup. Open the config where the name includes solrsearchcontentadvancedsearchforpage. Note the line context_filter: null. Open the config for solrsearchcontentadvancedsearchforblock. Change the context_filter line to null. Now the "Search sub-collections" checkbox is gone.

Who's this affect?

Site admins.

[kylehuynh205]

At UTSC, we implemented a checkbox in the configs to hide or disable the Include Sub-collection, we think it's more like a use case for us so we put it in another extended module. Looks like it can help for this.

We can make an PR with those options for this issue.