Delegate callback now returns instance of TwicketSegmentedControl

[dkun7944]

The current delegate callback makes it impossible to have multiple TwicketSegmentedControls within one class. This commit fixed this by adding the TwicketSegmentedControl instance to the delegate callback parameters.

[polqf]

@dkun7944 are you going to do the changes we talked about 😄 ?

[dkun7944]

@polqf Done!