Fixes the width of the slim-select inputs inside the filters by copying the style that would have been applied to the original selects (unless the select is empty)
Copies the font-size from the select
Since we're using the styles applied by the theme, the fix should be compatible with other themes besides the default one.
Since we're using the styles applied by the theme, the fix should be compatible with other themes besides the default one.
Before:![image](https://user-images.githubusercontent.com/472791/229573122-c05f0b40-9c04-4602-ac52-a5ddd39f5645.png)
After: Default theme:
Arctic Admin:
![image](https://user-images.githubusercontent.com/472791/229572747-cea8c2a4-caf6-4df2-83e7-17b10cac2749.png)