* objectstorage: remove `types` package and move `ErrNotExist` in base package
* objectstorage: Implement .Is and add helper `IsErrNotExist` for `ErrNotExist`
* util: Rename `ErrNotFound` to `ErrNotExist`
* util: Add `IsErr*` helpers and use them in place of `errors.Is()`
* datamanager: add `ErrNoDataStatus` to report when there's not data status in ost
* runservice/common: remove `ErrNotExist` and use errors in util package
Since they're not types common to all the services but belongs to the
configstore.
Next step will be to make them local to the configstore and not directly used by
other services since these types are also stored.
ErrInternal is an internal error that should be provided to the user (http api
will return a 500 with the error message)
It'll be used for any kind of error that are not auth or bad requests (like
errors to communicate to another service)
Don't create an ErrFromRemote wrapping the returned error but
wrap the ErrFromRemote
Also use xerrors Is/As to get the underlying error to return to api clients
while maintaining context for logging
Just a raw replace of "github.com/pkg/errors".
Next steps will improve errors (like remote errors, api errors, not exist errors
etc...) to leverage its functionalities
Handle the task dependencies conditions:
* on_success (default if no conditions are specified)
* on_failure
* on_skipped
Not the runservice won't stop run but continue executing tasks that depends on a
parent also if this is failed
* client: always parse the json error message field and return its contents
* Use ErrBadRequest and ErrNotFound in every handler and command
* Gateway: by default pass underlying service error (configstore, runservice) to
client keeping the status code and message. In future, if some errors must be
masked, we should change the specific parts that need special handling.