No implementation for some storage types which are listed in "Select storage type:" prompt

[ShivangMishra]

Describe the bug
The following storage types are not supported -

• FTP
• Box
• DropBox
• OData
  These storage types are listed in the Select storage type dropdown, but nothing happens when the user selects them. The code does not even check these storage types.

To Reproduce

1. Run mft storage add
2. Select any of the storage types listed above(eg. Dropbox) from the curses dropdown.

Expected behavior
Either the dropbox storage option should be implemented properly or there should be some feedback to the user that dropbox storage is not supported yet.

Screenshots