Organization correctly uses LocalizedName

Previously both name and display_name where being stored as String
types. However this does not correctly satisfy SAML Metadata
as these values are defined as LocalizedName (i.e. with a lang
identifier).

This commit has the model design correctly reflect underlying XML
schema.
Update inflection for URI and s/SamlUri/SamlURI
Add LocalizedURI SAML metadata model
Organization correctly uses LocalizedURI

Previously url was being stored as String type. However this does not
correctly satisfy SAML Metadata as these values are defined as
LocalizedURI (i.e. with a lang identifier).

This commit has the model design correctly reflect underlying XML
schema.
Add expectation for ACS service_descriptions
Breakdown SamlURI into individual models

By removing the type identifier and having actual types for each URI
represented in the database we're afforded much more flexibility
especially in terms of validation and relationship modelling per SAML
Metadata schema.
Allow developers to store local TODO actions
Add NameIDFormat as SamlURI for SSODescriptor
Add AttributeProfile for IDPSSODescriptor
 Add NameFormat for AttributeBase
Rework saml:Attribute model, closer to schema

The previous implementation of Attribute had residual modelling left
over from concepts within FR2 (such as approval and workflow) and thus
was not strictly to SAML metadata specification.

Approvals, workflows etc should complete outside of the SAML microservice
before data modification is made within this service.
Model EntityID as SamlURI with EntityDescriptor

The SAML specficiation dictates entity_id as a URI type and not as a
basic string as we had defined previously. This commit correctly
extends the modelling to make use of an EntityID model extended from
SamlURI.