[Enhancement] Allow text selection and copy in Entry and Editor controls

## Summary
Read only Editor and Entry controls should allow selecting text and displaying context menu on a long-tap-event to allow Copy.

## Intended Use Case
This feature is important when displaying apps that has long articles like social networking, blogging, news, etc.

Start by locating the Entry and Editor control implementations and their platform-specific behavior. Check how read-only controls handle text selection and long-tap context menus across the supported platforms. Done means users can select and copy text from read-only controls, with the behavior verified on the relevant platforms.

Written by the indexing model from the issue text.