(Inspired by this Discord conversation in the fabric discord)

I would like to suggest the addition of a new event, ServerChunkEvents.CHUNK_STATUS_CHANGE which fires each time a chunk changes its load type (ENTITY_TICKING, BLOCK_TICKING, FULL, INACCESSIBLE).

This is useful because CHUNK_UNLOAD is only fired when the load level of a chunk goes above 44, which is 11 levels after INACCESSIBLE. Some mods (including my mod) would like to know when a chunk is no longer accessible even if it is technically still "loaded".

Alongside this, the documentation of CHUNK_UNLOAD should be updated to clarify when Minecraft actually unloads a chunk, specifically that chunks do not unload immediately after becoming INACCESSIBLE, which is the main source of the confusion.

Resolved in #4541