Add namespaces to P4

[jafingerhut]

Status as of 2024-Sep-16: After the series of meetings in early 2022 described below, no one to my knowledge has returned to investigating this topic. The ideas discussed in the repository linked below might be useful to implement in some form, but it would be a significant chunk of work.

There was a series of meetings in early 2022 regarding this topic, trying to work out design details of one way to implement a namespace feature in P4. Many questions, answers, and notes from those meetings can be found in files checked into this repository, and its issues, and comments on those issues:

• https://github.com/jafingerhut/p4-namespaces