keymgr: Move FS operations out of KeyType impl
Note: this builds on top of !1256 (merged). It should be reviewed starting from keymgr: Create a separate error source for key corruption errors.
.
This tackles some error-related TODOs and moves fs
calls out of KeyType
(this is just the first part of the refactoring. The next steps are to move all fs-related things to a separate mockable ArtiFsProvider: FsProvider
object).
Edited by gabi-250