Replace template.load with template.load_async

[PowerfulBacon]

Our map loading system is commonly ported wrong because I made the mistake of not renaming the proc. We should have 2 procs:

• load, which loads and sleeps until the loading is finished
• load_async, which returns a task. This should deprecate returning map_loader and unify tasks and map loaders.

[github-actions]

This issue has been inactive for long enough to be automatically marked as stale. If this was a bug report and hasn't been addressed yet, and is still a problem, please don't hesitate to notify a maintainer.