Update Jenkins terminology

Summary:
The Jenkins project has opted for a new distributed architecture terminology:

• "controller" for the main instance
• "agent" for the instances running jobs

Ref T1650

Test Plan:

• rename the repositories for agents' Docker images
• recreate Jenkins containers on docker-001.
• build a job in CI, then CD

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T1650

Differential Revision: https://devcentral.nasqueron.org/D2419