Support free text selection and copy/paste by touch events in Widgets

Quick now supports it, Widgets should support it too.

Only a single word can be selected by touch, the touch handles do not appear. A context menu also should be opened near the selected text.

Long press on an input field should trigger the context menu (with the appropriate actions).
 
 
To copy a text in Chrome or in Quick:

1. First do a long press on a word. The word gets selected.
2. Then allow to fine-tune the selection with text sliders
3. Finally, show a context menu containing the "Copy" action

To paste a text in Chrome or in Quick:

1. Long press in a text input field shows up a context menu containing the "Paste" action.