ui: SurfaceFlinger layers viewer (com.android.SurfaceFlinger)

Adds a SurfaceFlinger layers viewer for the android.surfaceflinger.layers data
source. Inspired by the Android Winscope tool.

trace_processor: the winscope importer plugin now reports the timestamp bounds of
the winscope snapshot tables (SurfaceFlinger layers + transactions,
WindowManager, shell transitions, IME, ViewCapture, ProtoLog), mirroring the
video/audio frame importers. Previously a trace captured with only the winscope
data sources had empty trace bounds and the UI treated it as empty; now it opens
directly. Adds read access to those tables' `ts` column.

Surfaced two ways onto one shared session:
- A nested "SurfaceFlinger" timeline group with one track per display (real and
  virtual, e.g. a video-encoder/screen-recorder display, which are part of what
  SurfaceFlinger composited). Each track shows that display's snapshots as
  frame-numbered, colorized slices; selecting one shows a compact summary plus an
  inline layout preview and opens the page at that snapshot.
- A full-screen page (sidebar > SurfaceFlinger) with a display selector, snapshot
  time-slider, prev/next, and a jump-to-timeline button that selects the snapshot
  slice on that display's track. The snapshot index and timestamp are shown
  consistently in the page and the details panel.

Three panes:
- Surface: a rotatable, stacked 3D view of the selected display's layer rects,
  pure 2D-canvas projection (no WebGL). Camera angles follow the standalone
  tool's mapper3d (pitch = factor*PI/8, yaw = 1.5*pitch); gradient / opacity /
  wireframe shading; spacing slider; only-visible filter; per-rect hide + pin;
  click-to-select; and leader-line labels in a side gutter that never overlap and
  are themselves clickable.
- Hierarchy: the full cross-display layer tree with chips (visible / GPU / HWC /
  relative-Z / hidden / spy / duplicate), only-visible / flat / simplify-names /
  diff filters and search, and per-node hide + pin toggles.
- Properties: a header card (name + chips), a curated summary as a DataGrid (with
  clickable layer references) and the full proto dump as a filterable DataGrid;
  with diff on, layers are marked added/modified/deleted and the proto grid gains
  a Previous column.

A layer belongs to a display via its rect's group id, so the Surface scopes to
the selected display's composition while the hierarchy/properties span all
displays. Built from native widgets (Section, Tree, Chip, DataGrid, Checkbox,
TextInput, Select) and themed with the --pf-color-* variables, so it follows the
app's light and dark mode. Enabled by default.

Change-Id: I2222222222222222222222222222222222222222