Carbon coverage: Add tab structure

[RichKummer]

Designers expressed a need to organize the results pane of the Carbon coverage plugin. We can accomplish this with tabs above the issue item list. For now, this does not include the Hidden tab.

Functionality notes:

• Tabs only appear once the file or selection is scanned.
• Tabs can appear in a set order:
  1. All
  2. Color
  3. Type
  4. Components
  5. Effects
• Each tab only appears if associated issues are found. For example, if no Effects issues are found in a scan then the Effects tab will not appear. If any number of tabs appear, All appears.
• Each tab label includes the number of associated issues. For example, if 42 issues are found in the All category, then it will display as All (42). The same applies for each category label. These labels should update when the designer scans the file/selection.
  • In the future with the "hide" functionality, we should consider updating the label counter as the user marks an item as an exception, instead of only when scanning.
• Tabs should display an overflow button if the content would overflow off the plugin modal.