Protocol Engine: return protocol metadata on protocol file upload

[mcous]

Overview

As a user of the new ProtocolEngine-based upload-and-run system, I'd like to know metadata about my protocol when I upload it to my OT-2, so that I can better understand what I'm about to run.

In this case, "metadata" includes any of the following, if available:

• Filename(s) of the protocol
• Name (as in "title") of the protocol
• Author
• Description
• Last modification date
• Python Protocol API version
• JSON Protocol Schema version
• Protocol Designer version

Acceptance criteria

• Protocol engine POST & GET /protocols response models include metadata listed above
• (Internal) protocol resource model includes API version / schema version for correct simulation/run mechanics

Implementation details

• The metadata items listed are based on the information that the Opentrons App currently displays for RPC-uploaded protocols
• For JSON protocols, this is a straightforward parsing of the JSON
• For Python protocols, we should probably maintain our current strategy of inspecting the syntax tree for the metadata module variable
  • We could choose to from protocol_file import metadata or something similar
  • However, due to the likelihood of import side-effects, static analysis is safer
• Last modification date is only really meaningful for JSON protocols, where this is encoded in data
  • Only the client would know when a Python file was last touched, so don't worry about it in the HTTP API