Changes to subject indicators

Description

Making multiple changes to how we handle subject prefixes and values:

CreatedBy and Consumer
- Added support for /organisation/ in access subject authorization.
- Storing new subscriptions for an organisation as /organisation/ instead of /party/. One thing to note is that there are no subscription in any environment where CreatedBy or Consumer data have the /party/ prefix. They are all either /org/ or /user/. This means that at no point in time has anyone successfully created an organisation subscription.
Alternative subject
- Added support for alternative subject using /organisation/ as prefix. Keeping /org/ for backwards compatibility. This might be in use by external parties when setting subject filter on a subscription.

Other changes:

SubscriptionService.GetAllSubscriptions() where the only method taking consumer as input. Changed to use IClaimPrincipalProvider instead.
Removed support for Hungarian prefixes on variable names

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

[ ] User documentation is updated with a separate linked PR in altinn-studio-docs. (if applicable)