fix(azure): add product tag on all resources (#955)

<!--- Provide a general summary of your changes in the Title above -->

## Description
In order to separate resources in Azure for Arbeidsflate and
Dialogporten
<!--- Describe your changes in detail -->

## Related Issue(s)

- #{issue number}

## 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.](https://github.com/Altinn/altinn-studio-docs), if
applicable)

.azure/infrastructure/main.bicep

@@ -65,6 +65,7 @@ var namePrefix = 'dp-be-${environment}'
 
 var tags = {
   Environment: environment
+  Product: 'Dialogporten'
 }
 
 // Create resource groups