Add a "salt" property to the Client entity class.

Signed-off-by: Marios Sotiropoulos <mai1211@uom.edu.gr>
Implement the MsOauthAuthenticationService.

Signed-off-by: Marios Sotiropoulos <mai1211@uom.edu.gr>
Add the ClientDetails template.

Signed-off-by: Marios Sotiropoulos <mai1211@uom.edu.gr>
Add the ClientIdGeneratorInterface and its implementation.

Signed-off-by: Marios Sotiropoulos <mai1211@uom.edu.gr>
Increase the "users" table "id" field's length to 43.
Complete the Client Registration use case.

Except for the validation of the redirection URI.

Signed-off-by: Marios Sotiropoulos <mai1211@uom.edu.gr>