BAH-4033 | Enhancement. Support for passing task type through eventConfig.json

[mohan-13]

With the view of allowing implementers to allow configuring task types for the non-medication tasks, this PR brings in changes to read the task type from eventsConfig.json. This removes the hardcoding of nursing_activity_system as the task type for system generated tasks.

[mohan-13]

Relates to Bahmni/openmrs-module-fhir2Extension#65

[mohan-13]

⚠️ Breaking Change ⚠️
This PR brings in a breaking change to existing implementations.

1. Contract of eventsConfig.json

• type attribute in ConfigDetail model is updated as event
• Additional nullable property type is introduced in TaskDetail model
• Sample eventsConfig.json

[
{
  "event": "PATIENT_ADMIT",
  "tasks": [
    {
      "name": "Complete Insurance Pre-Auth Form",
      "type": "Documentation"
    }
  ]
},
{
  "event": "SHIFT_START_TASK",
  "tasks": []
},
{
  "event": "ROLLOVER_TASK",
  "tasks": []
}
]

2. Exception is thrown when the concept does not exist.
   When a taskType is passed and the concept is not available in the concept dictionary, then a Validation exception is thrown.

cc. @binduak @Arjun-Go @kavitha-sundararajan