Hide each icon in toolbar separately

[AlirezaDaryani]

• Add new class to make this possibility to hide each icon in toolbar separately in all possible constructors
• Background padding also handled in case of hiding all icons
• Usage wrote in the example
• Related comments added

[lively-bigyan]

@AlirezaDaryani Thank you for opening the pull request. I do however have doubts about merging these changes. In this last version of 0.7.0, we introduced a new mechanism that exposes the ImagePainterController object. This object allows users to have a high degree of customization if needed because they can create any button and add callback inside the button to do whatever action we previously did on each preset button callback. We are trying to move away from the approach of overloading a single class with parameters for each small action. I do like the fact that the control parameters are consolidated in a single class. But this approach is what we are trying to move away from so it goes against the direction we are headed for the package. Please let me know your thoughts on this.