Bake remotely

[nicolasochem]

This enables remote baking.

Instead of having baking & node containers in the same pod, this deploys one pod per baker.

Originally, they were clumped together because they needed shared access to storage.

The old method still works. bake_remotely requires a new top-level config bakers: in values.yaml

Other changes

• switch to oxford by default across the board (mkchain, default values yaml)
• mkchain defaults to bake_remotely now
• refactor args of mkchain to make it friendlier to rollup and DAL. e.g.:

mkchain --bakers 2 --dal-nodes 2 --nodes 2