Feature/ProximitySurfaceSelector

Adds the ProximitySurfaceSelector filter. It takes in two surface meshes and outputs two subset surface meshes of all faces within some distance of each other. As a note, the example is purely for visualization. It will not be in the merged code. The last step will be to remove it.

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 license header is in all new files
• Added iMSTK examples for all new major features (if any)
• Removed ConnectiveTissueExample (only used for visualization and debugging)