Deploy Penpot

Summary:
Allow to customize standard PostgreSQL image environment variables
used by Penpot.

Ref T1703.

Test Plan:
Unit tests provided for new module functions

Deploy on Dwellers, browse https://design.nasqueron.org

Reviewers: dereckson

Reviewed By: dereckson

Subscribers: inidal, fauve

Maniphest Tasks: T1703

Differential Revision: https://devcentral.nasqueron.org/D2597