feat: DH-21757: Allow widget plugins to register types as dashboard types

[mofojed]

• Allows widget plugins to register a type as a dashboard type, and create the dashboard payload
  • Avoids the current hack where the ui DashboardPlugin intercepts the panel open and then emits a dashboard creation, is more explicit about how it's handled
  • Also allows other plugins to potential register dashboard types
• Used by feat: DH-21757: WidgetPlugin support in deephaven.ui deephaven-plugins#1341, Enterprise draft at https://github.com/deephaven-ent/iris/pull/4653
• Leaves the door open for if we want to have an option for allowing dashboards to open as a panel by default (for now, you can just wrap a dashboard in a ui.panel)

[dgodinez-dh]

Changes look good. But looks like a few test failures.

[codecov]

Codecov Report

❌ Patch coverage is 59.18367% with 20 lines in your changes missing coverage. Please review.
✅ Project coverage is 50.08%. Comparing base (0b5774e) to head (1e8a064).

Files with missing lines	Patch %	Lines
...dashboard-core-plugins/src/panels/ConsolePanel.tsx	39.39%	20 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2679      +/-   ##
==========================================
- Coverage   50.28%   50.08%   -0.20%     
==========================================
  Files         774      774              
  Lines       44103    44148      +45     
  Branches    11372    11386      +14     
==========================================
- Hits        22178    22113      -65     
- Misses      21878    21989     +111     
+ Partials       47       46       -1     

Flag	Coverage Δ
unit	50.08% <59.18%> (-0.20%)	⬇️

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