Add GET /v1/analytics/sessions/behavior endpoint with reach-target and URL-param goal support

Description

Add a new GET /v1/analytics/sessions/behavior endpoint in CAEM that evaluates session behavior against experiment goals. The endpoint supports two goal types:

• Reach-target goal: Determines whether sessions reached a target page after visiting a reference page
• URL-param goal: Determines whether sessions contained a specific URL parameter during any event in the session

The endpoint accepts a behavior type, experiment context parameters (experimentId, runningId), and goal-specific required parameters. Includes service-layer dispatch with parameter validation and dedicated repositories for each goal type.

Acceptance Criteria

• GET /v1/analytics/sessions/behavior accepts behavior, experimentId, runningId, and goal-specific required parameters
• The endpoint returns reach-target goal results when behavior=reach-target is requested
• The endpoint returns URL-param goal results when behavior=url-param is requested
• Requesting a behavior value with missing required parameters returns a 400 error
• Reach-target goal correctly counts sessions where the target page was visited after the reference page
• URL-param goal correctly counts sessions where any event in the session contained the specified URL parameter
• Existing GET /v1/analytics/sessions behavior is not affected
• Unit tests cover service dispatch logic and parameter validation for all behavior values
• Unit tests cover SQL logic and edge cases for reach-target queries
• Unit tests cover SQL logic and edge cases for URL-param queries
• Postman tests covering the new endpoint are added to the CAEM Postman collection

Additional Context

Implementation repository: dotCMS/dot-ca-event-manager