Enhance R1 Interface API Specifications for Standard Compliance

Enhance R1 Interface API Specifications for Standard Compliance

Update the R1 interface API specifications and implementation to comply
with O-RAN standards and RFC 7807 guidelines. Several deviations from
O-RAN R1 specifications and API best practices were identified and fixed:

- Schema Consistency: Added missing fields (artifactVersion, owner) and
  ensured inputDataType/outputDataType are arrays with targetEnvironment included.
- Error Handling: Standardized error responses (400/404/500) to use
  RFC 7807 ProblemDetails format.
- Naming Consistency: Unified path parameters and schema naming to follow
  camelCase (e.g., id → modelId).

The artifactVersion and targetEnvironment fields are planned to be incorporated in a follow-up patch.

Issue-ID: AIMLFW-256

Change-Id: I01365edf62b25eab4b704c7c9c455802122b2ce2
Signed-off-by: JuheeShin <odong3094@khu.ac.kr>