Add missing features to `BitButtonGroup`

[Cyrus-Sushiant]

The BitButtonGroup component lacks several important features that limit its functionality and versatility. The following features need to be added:

1. Icon Button: Ability to show only an icon in each button.
2. ToggleButton: Support for toggle buttons within the group.
3. Center Alignment in Vertical Mode: Ability to align buttons to the center when the ButtonGroup is in vertical mode.