Add dashboard collaborators with access level
Add collaborators to a specific project dashboard. Requires 'project_id' and 'dashboard_id'. Supports JSON, form-urlencoded, and multipart data. Returns added collaborator details. Auth: 'PersonalAPIKeyAuth'. IMPORTANT REQUIREMENTS: 1. The dashboard must have restriction_level > 21 (not on the lowest restriction level). Use POSTHOG_PARTIAL_UPDATE_OF_A_PROJECT_S_DASHBOARD to set restriction_level to 37. 2. The user being added cannot be the dashboard owner or a project admin (they already have inherent access). 3. Currently only level 37 (edit access) can be explicitly specified. 4. Use POSTHOG_LIST_ORGANIZATION_MEMBERS_WITH_PAGINATION to find valid user UUIDs.