Support Public APIs - CopyText, CutText & PasteText

Support Public APIs - CopyText, CutText & PasteText

with the following prototypes and descriptions:

string CopyText(TextEditor textEditor) or string CopyText(TextField textField)

This function will copy the previously selected string into the clipboard and will return it.

string CutText(TextEditor textEditor) or string CutText(TextField textField)

This function will cut the previously selected string into the clipboard and will return it.

void PasteText(TextEditor textEditor) or void PasteText(TextField textField

This function will paste the most recent string in the clipboard stack into the text control.

Change-Id: I7dc8156e636f95b8acf8c350bfc7827419e239ca