Sr system user 8

[simen-rekkedal]

New Endpoint for System Register. Only the GetList part, since the rest of the CRUD is handled elsewhere

Description

Created APIController with GetList of RegisteredSystemDTOs for the Frontends pull down menu.

Related Issue(s)

• Chore: Keep relevant API calls like profile and authentication: a list of relevant API calls should be made #8
• Task: 9.15 Create SystemRegister APIController #67

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)
• All tests run green

Documentation

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

[Torgeir333]

Bra. Det er viktig å få BFF og Frontend i sync, spesielt i lys av Issue 232 (se Repo Wiki).