Implement some basics in UEFI fs
- Just getting some basics out of the way while waiting for #138236 to be merged.
- Adds `fs::canonicalize`. Should be same as absolute in case of UEFI since there is no symlink support and absolute path is guaranteed to be uniqe according to spec.
- Make `fs::lstat` same as `fs::stat`. Should be same since UEFI does not have symlink support.
- Implement `OptionOptions`.
cc ````@nicholasbishop```` ````@dvdhrm````
Matthias Krüger
b157594165