tracking: transition framework projects to flux-foundry

[garlick]

This is a tracking issue for integrating flux-foundry into flux-core and other projects that depend on these foundational classes.

• add config library #20
• Update flux-core to require flux-foundry
• Work out spec file changes for TOSS
• add python bindings #6
• deb: prepare to coexist with flux-core package #7
• deploy docker images from CI and update core projects (e.g. flux-core, flux-security) to use them
• transition outstanding issues from flux-core to this repo