fix(severity dropdown): uniformity for all severity dropdowns in filter and drawer

[sanchayan721]

Features:

1. Uniformity across dropdowns (in filter and inside drawer).
2. getSeverityInfo component added for better management of various severity themes.
3. Replaced labels using this function into the severity filter dropdown component.
4. Added the icons to the priority chips.
5. Background color to severity chips.

[marcbon]

use a boolean-like prop name for this to avoid misunderstanding