Fixing MouseButtonMapper by adding VirtualKeyMaps to the MouseButtons. Adding Manual key entry form to not require recording inputs. Upgrading project to .NET 8.0

[ryanbbernstein]

Fixes an error that occurs when trying to send a mouse button configuration.
Error occurs in the following code in MouseButtonMapper due to there not being any virtual key attributes:

var attr = member.GetCustomAttribute<VirtualKeyMapAttribute>();
_map.Add((val, attr.Key));

Adding new ManualKeyForm that lets you manually select a key and modifiers to add to the key sequence. Useful if you want to add keypresses for keys that are not available on your keyboard. Button is placed just below the record button.

Lastly upgrading the project to .NET 8.0

[ryanbbernstein]

Oops I did not realize that every change i pushed to my repo would be included in this pull request. Ill update the title.