Shaman cannot handle cases where the storage path is a symlink (i.e. cases
where `filepath.EvalSymlinks(storagePath)` does not return `storagePath`).
This caused macOS devices to fail the unit tests, because macOS uses a
symlinked path for temporary files.
This commit changes the unit tests, to always use the real path instead of
the OS-provided symlink. This does *not* fix the actual issue in Shaman,
for that see T99965.
Flamenco v2 allowed separate configuration of the Shaman file store and
checkout paths. This is now just one setting for "the storage". The file
store will be in `{storage}/file-store` and the checkout will happen in
`{storage}/jobs`.
This is not yet working, it's just a direct copy of the Manager of Flamenco
2, with Logrus replaced by Zerolog. The API has been documented in
flamenco-manager.yaml as a starting point for the integration.
