AuthModel loading at startup

[MarcAgate]

There should be a way to load the model directly from fuseki at application startup. Currently the model is rebuilt from auth0 and bdrc policies, then updated on fuseki.
While this MUST be the case for ldspdi (which is in charge of updating the auth Model when webhooks are trigerred), it doesn't have to be that way on iiifpres or iiifserv.
So two methods in refAuthModel : reloadModel (rebuilts it) and readModel() (which reads the model from fuseki)
Reload() is used in ldspdi, Read is used anywhere else.

[MarcAgate]

This has been adressed in v. 0.2.0 : readAuthModel() reads the model from fuseki and updateAuthData() rebuilts the model from auth0 and bdrc-auth-policies.