Change UiVerbosity to UiLayout and tighten up related implementations

[abey79]

Context

An important aspect of the DataUi infrastructure is the UiVerbosity enum passed by the caller, which specifies how "verbose" the UI should be. So far, verbosity levels have been relatively loosely defined: small, reduced, full. While flexible, this approach has two problems:

• It provides very little guidance for DataUi implementors on how to deal with each verbosity level.
• It provides callers very little guarantees on the kind of UI that might end up being generated for a given verbosity level.

Concretely, this makes some efforts difficult.

For example, #4161 requires all implementation for UiVerbosity::Small to fit inside half a list item, whereas some implementation actually span multiple lines.

Likewise, using full-span widgets such as list item in DataUi is complicated because it's currently ill-defined whether a give verbosity level implies that a full_span_scope is defined or not (#6246).

A very partial attempt at resolving this was included in #4416, where distinct verbosity level were created specifically for single-selection vs. multi-selection Selection Panel.

Current use of UiVerbosity

• UiVerbosity::Small:
  • InstancePath::data_ui() delegating to component's data_ui()
  • EntityLatestAtResults::data_ui() delegating to component's data_ui()
  • override_ui() delegating to component's data_ui()
  • DataFrame space view, for displaying component in the table
  • image_hover_ui delegating to TensorData::data_ui()
• UiVerbosity::Reduced: used in many places, but always as part of some hover tooltip
• UiVerbosity::LimitHeight and UiVerbosity::Full: only used by the selection panel

Propsal

• Rename UiVerbosity to UiLayout and change the variants to more closely capture the context and/or constraints they should respect: Rename UiVerbosity to UiLayout and make its variants more precise #6291
  • Small -> List
    • used within a ListItem
    • single line, short, capable of truncation
      • Style feature to have label truncate by default emilk/egui#4473
    • full_span_scope not defined
  • Reduced -> Tooltip
    • used within a tooltip
    • no interactive UI, for now no full-span UI because of All UI containers should ideally define full span ranges themselves #6246)
    • full_span_scope not defined
  • LimitHeight -> SelectionPanelLimitHeight
    • used in selection panel with multi-selection
    • very long list should be in height-limited scroll area
    • full_span_scope defined
  • Full -> SelectionPanelFull
    • used in selection panel with single selection
    • very long list may be unrolled as it will be enclosed in a scroll area
    • full_span_scope defined
• Create a release checklist test that extensively logs all possible components, such that it's easier to review all DataUi implementations.
  • Add a release checklist to check the UI for all components #6267
• Fix all current implementations such that they obey the constraints above

Related

• Use the ListItem style for the component list (in the Selection Panel when an entity is selected) #4161
• Improve the Selection Panel UI for components when a single item is selected #4416
• Migrate all full-span widgets to re_ui::full_span #6248
• All UI containers should ideally define full span ranges themselves #6246
• Style feature to have label truncate by default emilk/egui#4473