Closed doors logic

[wossnameGitHub]

New features:

1. Added algorithm to account for closed doors
   This means that from now on, the following things will never happen again:
   A) Levels being inaccessable due to closed doors
   B) The player running into a dead end and therefore a softlock due to closed doors
   Keep in mind that softlocking due to [missing items] is still completely possible, this closed doors algorithm is a whole different subject.

2. Added multiple small things to graph creation:
   A) closed doors are marked in red, and point in the direction that is still traversable even if the door is closed
   B) one-way-transitions are marked by using a dashed line
   C) temp disabled exits are marked in black

In order for those to be added:

• Massive update/overhaul to entrance_rando.py
• Quite large update/overhaul to graph_creation.py

[Avasam]

Went through a full review of graph_creation.

Only a very superficial look at the new rando logic, probably fine (the idea is sound, haven't checked the implementation in details yet).
The amount of global variables and context-specific top-level public methods we're using make me think that it might soon be time to think about making the "randomizer" it's own class.