Retrieve time tracking sources by source type for engagement

Retrieves time tracking sources for a specific engagement and source type.

• Use the engagement_id and source_type path parameters to fetch relevant sources for an engagement.
• For creating a time sheet, both work schedules and entry types are required.
• When updating time sheet entries, only entry types are needed, this endpoint provides the necessary data.

Typical use case:

• Retrieving entry types when modifying existing time sheet entries.