multi-user: Namespace Pipeline Definitions

[yanniszark]

@Bobgy @IronPan I understand that the current state of Pipelines is that Runs/Experiments are namespaced, but pipeline definitions aren't.
I recall from an older discussion that:

• You mentioned that users want a global pipeline registry, which is a very valid use-case, so that's why you keep pipeline definitions global for now.
• We discussed about having both namespaced and global pipelines, based on an extra field in the database schema.

Given that pipeline definitions are essentially code and it doesn't seem reasonable to ask all teams to share all their code, what is your plan about supporting namespaced pipeline definitions (alongside global pipeline definitions), so that teams can keep their pipelines/code isolated?
I couldn't find a relevant issue so I created a new one.

[Bobgy]

/cc @IronPan

I don't think we have a plan to support that unless we gather further feedback. You are welcome to contribute the feature flag.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[Bobgy]

/lifecycle frozen

This is one of the top feature requests from multi user support issue.

[Bobgy]

Duplicate of #4197

Let's use that issue to track this.