If `targetEntryPointPath` is provided to `mainNgcc` then we will now mark all
the `propertiesToConsider` for that entry-point if we determine that
it does not contain code that was compiled by Angular (for instance it has
no `...metadata.json` file).
The commit also renames `__modified_by_ngcc__` to `__processed_by_ivy_ngcc__`, since
there may be entry-points that are marked despite ngcc not actually compiling anything.
PR Close#29092
Now the public API does not contain internal types, such as `AbsoluteFsPath` and
`EntryPointJsonProperty`. Instead we just accept strings and then guard them in
`mainNgcc` as appropriate.
A new public API function (`hasBeenProcessed`) has been exported to allow programmatic
checking of the build marker when the package.json contents are already known.
PR Close#29092
Pete Bacon Darwin