Call Serialize implicitly when assigning to a string

[alex6dj]

Every time a ButtonBase is instantiated and CallbackData get used as a Value for it, .Serialize() need to be called because Value only accept an string.

So with this instead of:

var new button = new ButtonBase("Edit", new CallbackData("a", CallbackValues.Name).Serialize());

Now you can do:

var new button = new ButtonBase("Edit", new CallbackData("a", CallbackValues.Name));

So no more .Serialize() call.

[MajMcCloud]

Added for ease of use for the CallBackData structure. Thanks for the PR and commit 👍