GitLab: Add default pagination limits

[Shubhank-Jonnada]

List actions don't enforce default pagination limits.

Suggestion: Add explicit per_page defaults in code.

Affected actions:

• list_projects
• list_issues
• list_merge_requests
• list_commits
• list_branches
• list_pipelines
• list_pipeline_jobs
• list_repository_tree
• list_container_registry_repositories
• list_container_registry_tags