Currently all of our migrations are set up to find the tsconfig paths within a project,
create a `Program` out of each and migrate the files inside of the `Program`. The
problem is that the `Program` can include files outside of the project and the CLI
APIs that we use to interact with the file system assume that all files are within
the project.
These changes consolidate the logic, that determines whether a file can be migrated,
in a single place and add an extra check to exclude files outside of the root.
Fixes#39778.
PR Close#39790
The default value for `relativeLinkResolution` is changing from 'legacy' to 'corrected'.
This migration updates `RouterModule` configurations that use the default value to
now specifically use 'legacy' to prevent breakages when updating.
PR Close#38698
Kristiyan Kostadinov
Andrew Scott