Ability to add a new control to the _buildActionBar function

[AhmadFalahian]

I want to add a close button to the controls, after checking the code I realized that it is necessary to add this feature to the controls defined in this package so that I can add the control I want, for example in the MaterialControls class and in the _buildActionBar function This feature needs to be added. Thank you for adding this feature to your package

[diegotori]

@AhmadFalahian you're gonna have to fork this repo from master like everyone else and then re-submit your changes as a new PR.