Add hidden rooms

[vadi2]

Brief overview of PR changes/additions

Add hidden rooms as a feature, so the mapper can be aware of a room but not necessarily draw it.

Motivation for adding to Mudlet

Closes #783

Other info (issues closed, discussion etc)

[github-actions[bot]]

	Warnings
:warning:	PR makes changes to 12 source files. Double check the scope hasn't gotten out of hand

Generated by :no_entry_sign: dangerJS against 9053868363be505f1d77d5937c5de91a8d934463

[vadi2]

/create links

[add-deployment-links[bot]]

Hey there! Thanks for helping Mudlet improve. :star2:

Test versions

You can directly test the changes here:

• linux: https://make.mudlet.org/snapshots/e3d485/Mudlet-4.19.1-testing-pr8443-90538683-linux-x64.AppImage.tar (commit 90538683)
• osx intel: (download pending, check back soon!)
• osx arm: https://make.mudlet.org/snapshots/b4d414/Mudlet-4.19.1-testing-pr8443-90538683-arm64.dmg (commit 90538683)
• windows 64 bit: https://make.mudlet.org/snapshots/94a32b/Mudlet-4.19.1-testing-pr8443-90538683-windows-64.zip (commit 90538683)

No need to install anything - just unzip and run. Let us know if it works well, and if it doesn't, please give details.