This step converts as many explicit accesses as possible in favor of direct imports from the modules in which things were declared. This restores the code (as much as possible) back to how it looked originally before the explicitify step, e.g. instead of "ts.Node" and "ts.Symbol", we have just "Node" and "Symbol".
This step converts each file into an exported module by hoisting the namespace bodies into the global scope and transferring internal markers down onto declarations as needed.
The namespaces are reconstructed as "barrel"-style modules, which are identical to the old namespace objects in structure. These reconstructed namespaces are then imported in the newly module-ified files, making existing expressions like "ts." valid.
* Refactor node factory API, use node factory in parser
* Move UnparsedSource nodes to factory
* Make most Node properties read-only
* Make pos/end/parent and JSDoc 'comment' read-only
* Update function/constructor-type factories
* Remove treeStateObserver
* Simplify Debug.deprecate
* Remove unused factory methods, simplify lazy factory methods
* Fix base factory used for source file updates
* Update test baseline due to merge from master
* Rename factory methods to be more consistent (#39058)
* Move most harness globals into namespaces
* Remove forward declaration from `createMapShim` and move all `Map` declarations into one file
* A small pile of more changes to get the harness transforming
* Add support for sharding tests across multiple workers
* Disable unittests when runners are expressly provided (unless they contain the unittest runner)
