Add "Clone User Profile" Functionality

[mathdeziel]

Now that multiple users are supported, this PR introduces a new "Clone User" feature, allowing to quickly duplicate an existing profile's mutations to a new profile.

This is especially useful in cases where a profile requires many mutations since only the values have to be changed in the new profile.

Feature description:

• New "Clone User" button added next to "Add User" in the Configuration window.
• Clicking the "Clone User" button will create a new profile with createDefaultProfile like with the "Add User" button.
• A deep copy of the selected profile's mutations is assigned to the new profile.
• The suffix "CLONE" is added to the name.
• The new profile is automatically selected.

Screenshot of the UI with the new button:

[bebiksior]

LGTM :D Thanks!!