task_local context over context objects

- interner impls logically separate from API in orchid-base (default host interner still in base for testing)
- error reporting, logging, and a variety of other features passed down via context in extension, not yet in host to maintain library-ish profile, should consider options
- no global spawn mechanic, the host has a spawn function but extensions only get a stash for enqueuing async work in sync callbacks which is then explicitly, manually, and with strict order popped and awaited
- still deadlocks nondeterministically for some ungodly reason

orchid-base/src/lib.rs

@@ -3,7 +3,6 @@ use orchid_api as api;
 
 pub mod box_cow;
 pub mod boxed_iter;
-pub mod builtin;
 pub mod char_filter;
 pub mod clone;
 pub mod combine;
@@ -14,6 +13,7 @@ pub mod id_store;
 pub mod interner;
 pub mod iter_utils;
 pub mod join;
+mod localset;
 pub mod location;
 pub mod logging;
 mod match_mapping;