Associated Issue: #4410

Summary of Changes

• Added icon prop to dropdown (every dropdown requires icon input)
• Breakpoint dropdown (BD) toggle .svg to "+"
• BD returns dropdown of breakpoint actions

1. Pause on next statement
2. Pause on exceptions
3. Pause on uncaught exceptions
4. Ignore exceptions

Test plan:

• Clicking '+' in the breakpoints pane toggles the BD
• Clicking an action causes .svg image highlight
• Clicking an action also causes '+' image highlight
• Selected action executes on exception (or exception is ignored)
• Resuming program execution allows program to continue until next exception
• Clicking '+' again (without selecting an action) closes the BD

TODO:

• Adjust dropdown width to fit parent
• Remove dropdown scroll-bars
• Update L10N.getStr for each dropdown option
• Add menu items (with corresponding images)
• Add menu item implementation
• Add hover animation
• Change Svg implementation of dbgButton to img (to accommodate mask)
• '+' icon highlights when in execution state (when execption are not ignored)
  - [ ] Remove CommandBar options as needed
• Add dropdown as feature and toggle command bar feature as needed