Previously the same `Renderer` was used to render typings (.d.ts)
files. But the new `UmdRenderer` is not able to render typings files
correctly.
This commit splits out the typings rendering from the src rendering.
To achieve this the previous renderers have been refactored from
sub-classes of the abstract `Renderer` class to classes that implement
the `RenderingFormatter` interface, which are then passed to the
`Renderer` and `DtsRenderer` to modify its rendering behaviour.
Along the way a few utility interfaces and classes have been moved
around and renamed for clarity.
PR Close#25445
c613596658