Deprecate world names

[Machine-Maker]

World's should not be identified with strings, they should be identified with namespaced keys.

TODO

• Check that timings reports won't be affected
• World component display name
• MapItemSavedData's level name usage
• CraftServer's Map<String, World> using level name
• World adventure's Name pointer
• Move hunks into their correct patches
• Paper comments in the right places

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.