* Adding health check controllers - getAll & getGroupByName
* Adding HealthCheckGroup mapper
* Adding viewModels
* Adding a factory for building a health check group with result view model
* Registering the mapper and factory
* Updating OpenApi.json
* Remove unnecessary checks - we instantiate the target before calling the Map()
* Adding ProducesResponseType for GetAll()
* Fixing usings
* Making checks required for a health check group
* Adding OK() around result to be explicit
* Adding default values to skip and take
* Adding Umbraco.Code comments
* Removing ? from HealthCheckGroupWithResultViewModel return type
* Move the grouping creation to the factory
* Adding Actions[] for each health check + mapping
* Defaulting ValueRequired to false
* Refactoring routes - from health-check to health-check-group
* Move to HealthCheckGroup folder
* Fix OpenApi.json
* Changing class name and making Key of HealthCheckActionViewModel non-nullable
* Fixing namespace
* Migrating ExecuteAction endpoint
* Add execute-action endpoint to OpenApi.json
* Use Task.FromResult() around the action result
* Fixing namespaces and swagger group name
* Fixing naming of the key in the health check action
* Fix tag names in OpenApi.json
