Track the status of a File and normalize file paths.
Review Request #12074 — Created Feb. 23, 2022 and submitted
Filenow tracks the status from a
created/deleted/modified/copied/moved states), which we'll be able to
use to make smart decisions when applying changes to files.
It also normalizes the file paths, ensuring that they're in the format
required for the OS and that all relative components have been
Relevant unit tests pass (can't currently run the whole suite).