Add QA check for include ordering in .dme files

[blinkdog]

About The Pull Request

I talked with @Madtankdriver on Discord yesterday, and he pointed out that Starfly doesn't build properly from a ZIP download from GitHub.

I was able to reproduce the error, and it seems the Windows desktop application DreamMaker will re-arrange the #include order of the files to a fairly specific ordering; to wit: files before folders, then alphabetically, recursively down the tree.

So, for example, the first eight entries in Starfly's dme file are:

#include "_maps\_basemap.dm"
#include "code\__byond_version_compat.dm"
#include "code\_compile_options.dm"
#include "code\_debugger.dm"
#include "code\world.dm"
#include "code\__DEFINES\_click.dm"
#include "code\__DEFINES\_globals.dm"
#include "code\__DEFINES\_profile.dm"

_maps and code are both folders, and _ comes before c alphabetically, so the path beginning with _maps comes first.

code\world.dm and code\__DEFINES\_click.dm, the folders code are identical, so we compare on world.dm and __DEFINES. Here world.dm is a file, so it comes before the folder __DEFINES in the ordering, despite __DEFINES coming before world.dm alphabetically.

We can manually edit the .dme file, and our CI pipeline will build the file with the manually edited ordering just fine.

However, users who download our code and click Compile in DreamMaker will get a bunch of errors when DreamMaker re-arranges the files into DreamMaker canonical ordering.

This PR adds a GitHub Action to perform a QA check to ensure the ordering in the .dme file is the canonical DreamMaker file ordering. If it fails, it tells the PR author that this change will likely prevent the code from building when people use it with DreamMaker.

Why It's Good For The Game

Being able to Compile and run the code with standard DreamMaker tools is important.
People can try things out on private servers they run locally.
The entry level to start coding / mapping / making sprites on BYOND games is DreamMaker.

Our code should be able to Compile and run when people download a ZIP from GitHub.