This is now self-maintaining and doesn't rely on the async pool to wipe its ass on task completion. Instead, the garbage collector will cause thread-local data to be automatically released when the async task is garbage-collected on the main thread.
This is problematic because child level providers can forget to override the provider name of their parents, and then override them by error. Instead, they should be used in a mapping fashion to make sure they are unique and not inherited.
Also, the old method did not permit registering multiple aliases for the same provider. This now makes that possible.
This is a major change to the way block metadata is handled within the PM core. This separates variant metadata (which really ought to be part of the ID) from state metadata, and in a couple of cases flattens separate states of blocks together.
The result of this is that invalid variants can be much more easily detected, and additionally state handling is much cleaner since meta is only needed at the serialize layer instead of throughout the code.
This brings two plugin-breaking changes: AsyncTask->onCompletion() and AsyncTask->onProgressUpdate() no longer accept Server parameters.
This now allows for the functionality of AsyncPool and AsyncTask to be tested outside of a Server.
I am eating my own words this once, because having the tester plugin as a separate repository makes no sense - it is just added barriers to writing proper tests with no actual benefit. Since the tester plugin is specifically intended for CI, it doesn't make sense for it to be in its own module.
The original regex almost completely failed at its objective, because it a) only worked if there was no value for the key, and b) did not prevent all such occurrences getting transformed, while quoting patterns that would not get transformed anyway.
