Use separate icon for buttons that show a drop-down

This patch does two things

1. Try to separate icons we use. Sometimes options open in a new dialog...other times they open in a drop-down menu. It would be good to separate out the icons a little better to know what will happen when you click
2. Fix the brush preset resource chooser so it updates better with theme changes

This is the issue for #1 in a bit more explanation. #1 shows an icon we use for dialog options that popup. #2 also has the same icon...but this one shows a drop-down of options. #3 is a new one Deif Lou started to use to show which ones are drop-downs. My proposal is to make all the drop-down menus use the ... menu (which is this patch).

Test Plan

Went through the code and looked for instances of the "configure" icon and the "view-choose" icon. Updated the icons to the ... one ("hamburger_menu_dots") that are drop-down menus.

Formalities Checklist

• I confirmed this builds.
• I confirmed Krita ran and the relevant functions work.
• I tested the relevant unit tests and can confirm they are not broken. (If not possible, don't hesitate to ask for help!)
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