[WIP] feat: Add support for legacy enterprise users

[elsand]

This add support for Altinn 2 legacy enterprise users ("virksomhetsbrukere")

Description

This introduces the concept of "user types", and generalizes IUserNameRegistry in order to support legacy Altinn 2 enterprise users, and adds additional extension methods in ClaimsPrincipalExtensions. This should lay some of the ground work required to support the new system users.

This means we no longer require a pid claim to be present in EU-endpoints requiring authorization; a urn:altinn:userId + urn:altinn:username or valid org. number in consumer will be deemed sufficient, and will cause a authorization request to be made. Altinn Authorization already utilizes urn:altinn:userid when enriching the request with roles if a resource party is supplied, so this makes it possible to use enterprise users (which don't have a pid claim) to use Dialogporten.

Allowing just a consumer claim will open for XACML policies with rules identifying specific organization numbers. This is not used in Altinn-contexts today, but it makes little sense to actively not support it as it might be more relevant in services external to Altinn.

This also introduces middleware to validate whether a valid user type is present. IUserNameRegistry and handlers have been refactored to assume that this is handled.

Tasks/considerations

• The seen log must be expanded with a field for usertype, such that Håndter feilende oppslag på navn for "seen by" activities #387 can be implemented properly
• Should there be more user types for service owners (ie. having an "org"-claim), and service owners on behalf of end users (per Utvide tjensteier-detalj-API med parameter for sluttbrukers fnr #386) ?

Related Issue(s)

• Utvide tjensteier-detalj-API med parameter for sluttbrukers fnr #386
• Håndter feilende oppslag på navn for "seen by" activities #387

Verification

• Your code builds clean without any errors or warnings
• Manual testing done (required)
• Relevant automated test added (if you find this hard, leave it and we'll help out)

Documentation

• Documentation is updated (either in docs-directory, Altinnpedia or a separate linked PR in altinn-studio-docs., if applicable)

[sonarqubecloud]

Quality Gate passed

Issues
2 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[elsand]

Mht seen-log må vi få inn userType i databasen også. Men mht til #386 ønsker vi nok ikke å ha den med i hashen eller sjekk om om isCurrentUser ..?

[elsand]

Ser det bør gjøres en hel del refaktorering for å introdusere et slikt brukertype-konsept. Legger denne litt på is inntil videre; dette går også i beina på PR628