feat: 3615 add button for create new subform in nextrecommendedaction

[JamalAlabdullah]

Description

• Added new buttom (Opprett et nytt skjema) inside the nextReccomendAction to add a new subform.
• Added a new component called CreateNewLayoutSet for rendering a new StudioCard when the user clicks the buttom (Opprett et nytt skjema)
• Save the new added subform to other subforms.
• Added tests
• NOTE: For this issue the new StudioCard includes just input for adding a new subform, and binding with datamodel will be fixed in a seperate issue
• Here is the solution for now:

https://github.com/user-attachments/assets/04f0333b-adc5-4a1f-9038-55a3a58200cc

Related Issue(s)

• #13615

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

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