REFAC: Vulkan removed

Removes Vulkan from iMSTK. Feel free to look around see if I missed some bits. Built on mine.

PR Checklist

• No API changes were made (or the changes have been approved)
• No major design changes were made (or the changes have been approved)
• No new dependecies were added (or the new dependencies have been approved)
• Added test (or behavior not changed)
• Updated API documentation (or API not changed)
• Ran the CodeFormatEnforcer task and verified the header is in all new files
• Added iMSTK examples for all new major features (if any)