[BUG]: Lead Group +MATLAB Won't Exit if Errors

[virati]

Describe the bug
Lead Group GUI does not close if there are errors anywhere in leadfigure_CloseRequestFcn(. This prevents MATLAB from closing as well.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'lead group'
2. Click on any folder that has only read only access
3. GUI will error on 'read only' directory.
4. Try to close the GUI - error will prevent exit
5. Try to exit MATLAB - error will prevent exit.

Expected behavior
Close functions should not save without explicit approval. Close functions should simply close, not hold up the entire process requiring task manager/sigterm.

Environment:

• OS: All
• MATLAB version: all
• Lead-DBS version: v3.2
• Lead-DBS setup: cloned from repo, develop branch.