Fix Apply button crashing on no selection

[viciousAegis]

Pull Request template

Purpose / Description

col.buildSearchString was getting an empty node, thus raising the error. This takes care of it by returning early if the search is empty.
Side Note: Should buildSearchString handle empty nodes?

Fixes

Fixes #11872

Approach

This takes care of it by returning an empty string early if the search is empty, so buildSearchString is not called

How Has This Been Tested?

Manually on my phone

Screenrecorder-2022-07-17-10-57-38-952.mp4

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Checklist

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• You have not changed whitespace unnecessarily (it makes diffs hard to read)
• You have a descriptive commit message with a short title (first line, max 50 chars).
• Your code follows the style of the project (e.g. never omit braces in if statements)
• You have commented your code, particularly in hard-to-understand areas
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[BrayanDSO]

I think that disabling the Apply button if there isn't anything selected would be a nicer ergonomic fix.

If it would be best to implement it now or later when the other filter options are added, I don't know. As you're the implementer, you should have a better idea of when.

[viciousAegis]

Yeah, that makes sense, I'll remove all functionality on it for now as a temp fix, and i'll disable it later when I have some more free time

[Arthur-Milchior]

It's not clear to me how you'll generalize it to a search with multiple options such as Note Type, but this is clearly a valid PR so I merge.
I may have a slight preference to return Null instead of "" to indicate a special value, especially if you do a test later, but not enough to block on it.

My main question is:

• let's say you already have a search in the searchbar. You open the filter sheet. You select nothing and click apply. What is the expected behavior. I believe that removing the search would be more natural, as you'd apply the filter sheet's selection, and so don't filter anything anymore. However, I admit that this case would probably lead to a long discussion with no right answer as two users may have different intuition here.

Relatedly: we may consider a special case where, if the user selected all colors and also "no flag", this node is also removed. Just to simplify the query