Refactoring of ButtonAsisst (#1868)
Refactoring of ButtonAsisst (#1868)

- Removed class comment (provides no actual information and will be misleasing, if the class is extended)
- Streamlined attached property
ButchersBoy/MaterialDesignInXamlToolkit,ButchersBoy/MaterialDesignInXamlToolkit,ButchersBoy/MaterialDesignInXamlToolkit