Introduce new GenerateMetadataTask Gradle task

[kimeta]

Currently, when a user wants to generate test and metadata for a library, we provide a ContributionTask Gradle task that creates the test and metadata directory structure and executes an agent to collect metadata and populate the metadata directories.
The ContributionTask is an interactive task comprising two components:

1. A ScaffoldTask that generates the test and metadata structure
2. A configuration and execution component that sets up the agent and runs it to collect and populate the appropriate metadata

We want to create a separate Gradle task called GenerateMetadataTask that handles only the second component (agent configuration and metadata collection). Unlike the current interactive approach, this new task will retrieve property values programmatically rather than collecting parameters through an interactive CLI menu.