Build a crossword player experience

[SiAdcock]

The crossword player available in the Guardian Digital Editions app will utilise the same crossword player library as that used by DCR-rendered web pages.

The player will form part of the same single page app defined in #12800

Requirements:

• There is no need to store user progress through the puzzle i.e. if the user closes the webview by navigating to another part of the app and then later re-opens the crossword, they will not see previously completed answers.
• There is no requirement to navigate back to the crossword selection screen from the crossword player