Basic Manifest Editing

Create an interface for editing saved manifests.

**User Paths**
_Entering with a manifest_

- How can I change out the manifest?
- What am I presented with as an editing platform?

_Entering without a manifest_
- How to supply a manifest to the interface?
- Is Manifest in RERUM check. If not, offer to bring it in. Otherwise warn that it may not be possible to actually edit it.

**Typical Editing Questions**
How deep does validation go when attempting to save an edited manifest?

Do we call out warnings for key:value things we don't understand?

What happens when there is a successful save of an edited manifest? What does the user see next?

What happens when there is an unsuccessful save of an edited manifest, or a manifest severely fails even basic validation?

Can we incorporate Deep Codex with this?