Persistent Dashboard

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Is your feature request related to a problem? Please describe the problem.

Aspire 9 added persistent containers, but could the same thing be done for executables (see #6466), in particular the dashboard. I can see a lot o value with a persistent dashboard:

- Keep previous traces / metrics /logs around in memory so you can compare a trace form your latest compilation to a trace from your preview iteration.
- Be able to make use of aspire outside of your apps themselves - e.g. maybe you have unit tests / integration tests which could publish traces to otel. (Right now if you try and run those in VS, modifying your tests usually causes VS to rebuild your app, and thus kill your apphost process and the dashboard with it.)
- Improve perceived responsiveness of Aspire as the dashboard won't need to be started from scratch on later runs.
- A cheat to sidestep some of the `Filed to bind` errors we see around the dashboard (see #8592 )

### Describe the solution you'd like

A persistent dashboard.

### Additional context

_No response_

Beginne damit, den verwandten Issue #6466 zu lesen und nachzuverfolgen, wie das Aspire-Dashboard über apphost-Ausführungen hinweg gestartet und beendet wird. Eine vollständige Lösung würde das Dashboard über Neubauten der ausführbaren Datei hinweg aktiv halten und Traces, Metriken und Logs zum Vergleich bewahren, einschließlich der von Tests veröffentlichten Telemetrie.

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