enhance File operations
Would be nice to add some more operations to the File menu:
- Ability to move/rename files - move/rename the open file but don't necessarily save it yet if there are unsaved changes and don't close the tab you are working in, the current tab just changes to editing the file in the new location.
- Ability to delete files - close the open file and then delete it
- Save as Copy - save the current file as a new filename, but keep editing under the original filename unsaved in the original tab
- Save as Copy and then open copy in new tab - save the current file as a new filename and then open the new filename in a new tab while retaining the original filename unsaved in the original tab.