Design and implement: app / recording / blueprint selection GUI

[jleibs]

Rerun currently has 3 related concepts relevant to the given state of the viewer: "app", "recording" and "blueprint."

The current naive implementation has 2 menu items: 1 for recordings and 1 for blueprints. Nothing precludes you from manually selecting incompatible recordings and blueprints.

There are still lots of open questions and ideas around how to handle this. 3 proposals that have come up so far:

Proposal 1: Recording-centric

• Show all loaded recordings as tabs #1905
• Each recording always gets its own tab
• Within a recording tab, only show the matching blueprints based on app-id
• Open question: what happens if you load a blueprint or run a blueprint-app with a different app-id?

Proposal 2: App-centric

• Each app gets its own tab
• When a new recording or blueprint associated with a specific app comes in or is opened, auto-switch to that app:
• Within the context of an app, by default, you only see the Recordings/Blueprints of the matching app.
• Open questions: how do you show two recordings of the same app?

[emilk]

We've decided on limiting each Rerun Viewer to only have one blueprint loaded at a time. This means each recording can get its own tab. Mårten is in the process of designing that.

[emilk]

Closing in favor of:

• Show open recordings in side view above blueprints #2298