Make map width fit to window size

[faucomte97]

Task Description

In Rapid Router, we want the level map to automatically fit the right hand side window when loading the level. This is to save users having to zoom in and out.

A solution to this had been implemented before which set the paper width and height to 100%:

#1516

but this solution caused a side issue:

#1543

which was then fixed by reverting the original code:

#1609

We'd like to reinstate the 100% height and width but without causing the level editor to go wonky.

Acceptance Criteria

• Set the paper's width and height to 100% only when playing a level, not when creating one.

[faucomte97]

Closing - restructure will fix this