Merge Feature/otoEditor to master

[dantemattson]

Strings.axaml:

• Added oto.exportoto as "Export Oto"

SingersDialog.axaml:

• Added export oto button
• Reordered otogrid datagrid columns: File first, color last
• Added more control to the otogrid with CanUser... and specifying AutoGenerateColumns, ClipboardCopyMode and SelectionMode and TwoWay binding of the oto items for saving

SingersDialog.axaml.cs:

• Add ExportOtoButtonClick function