[Scons] Implement module dependency sorting.

Modules can now call:

env.module_add_dependencies(name: str, deps: list, optional: bool)

To add required or optional dependencies during the "can_build" step.

Required dependencies will be checked and the module will be not be
enabled when they are missing, printing a warning to notify the user.

modules/theora/config.py

@@ -1,7 +1,8 @@
 def can_build(env, platform):
     if env["arch"].startswith("rv"):
         return False
-    return env.module_check_dependencies("theora", ["ogg", "vorbis"])
+    env.module_add_dependencies("theora", ["ogg", "vorbis"])
+    return True
 
 
 def configure(env):