Code coverage up to 95%

[jp-tosca]

This pull request includes a series of changes to the edu.harvard.iq.dataverse_hub project, focusing on code refactoring, the addition of unit tests, and the renaming of test files for better organization. The most important changes are summarized below:

Code Refactoring:

• Renamed fields in AccessToken from token_id to tokenId and user_id to userId, and added getter and setter methods, along with toString and equals methods. (src/main/java/edu/harvard/iq/dataverse_hub/model/AccessToken.java)
• Updated AccessTokenRepo to use the new field names in the query. (src/main/java/edu/harvard/iq/dataverse_hub/repository/AccessTokenRepo.java)
• Removed the isGdccMember method from Installation.java and replaced it with getGdccMember. (src/main/java/edu/harvard/iq/dataverse_hub/model/Installation.java)
• Removed an unused method findByDVHubId from InstallationService.java. (src/main/java/edu/harvard/iq/dataverse_hub/service/InstallationService.java)
• Added null check in UserService.validateRequest method to handle null requests. (src/main/java/edu/harvard/iq/dataverse_hub/service/UserService.java)

Addition of Unit Tests:

• Added unit tests for various classes including ServerMessageResponse, ErrorResponseController, InstallationController, OpenAPIController, AccessToken, InstallationDao, ScheduledJob, VersionInfoDao, TokenAuthFilter, and InstallationService. (Multiple files)

Renaming of Test Files:

• Renamed several test files to better reflect their purpose and location within the project:
  • InstallationGitImporterTests.java to scheduled/InstallationGitImporterTests.java
  • VersionDVInstallationCheckTests.java to scheduled/VersionDVInstallationCheckTests.java
  • RestHelperServiceTests.java to service/RestHelperServiceTests.java
  • ScheduledJobServiceTests.java to service/ScheduledJobServiceTests.java