BOSH auto-sizes resource pools now

This is great for errands - their VMs don't get created until the errand is being run.
Rename haproxy job template to proxy

[#83244566]
Rename haproxy job to proxy

[#83244566]
Merge remote-tracking branch 'origin/pr/31' into develop
'plan_updateable' defaults to true in generated manifests
Unpartition all nodes in AfterEach

- Primarily so BOSH does not get confused by leaving nodes in a partitioned state
- Also inline method into broker tests to avoid indirection [#84136048]
Avoid unpartitioning mysql node in AfterEach

This can result in a corrupt MariaDB cluster (see [#81697860]). [#84136048]