List drawn shapes under Draw, with icon shapes and colour swatches

Each shape drawn by hand gets a row under Draw, as Import's files do: its
colour swatch, its name, and show/hide, fly-to and remove. A shape is named
in its row, and its swatch opens the five colours there, so labelling and
colouring happen after a shape is drawn and can be seen, instead of in a
field filled in beforehand. Area, Line and Pin become icon buttons, named
for screen readers and tooltips, and the colour for the next shape is a row
of swatches instead of a dropdown.

The annotation engine gains per-mark remove, setHidden, restyle and frame,
and onChange so the list follows the board. A hidden mark stays on the board
at alpha 0, a renamed line keeps its length, and fly-to frames a line by its
whole path. Voice marks are not listed.

The Draw, form-field and segmented-control gates drive the new controls;
swatches are checked as chips, not segments.

src/i18n/locales/zh-CN.json

@@ -2657,14 +2657,15 @@
   "Scope edge feather": "视域边缘羽化",
   "Scope edge feather as a percentage of the keyhole radius": "视域边缘羽化，以视域半径的百分比表示",
   "Draw on the world — click vertices, double-click or Enter to finish, Esc to cancel": "在地球上绘制——单击放置顶点，双击或按 Enter 完成，按 Esc 取消",
-  "Shape": "形状",
   "Shape to draw": "要绘制的形状",
   "Area": "面",
   "Line": "线",
   "Pin": "图钉",
-  "Label (optional)": "标签（可选）",
-  "Label for the drawn shape": "绘制形状的标签",
-  "Colour of the drawn shape": "绘制形状的颜色",
+  "Colour of {name}": "{name} 的颜色",
+  "Change the colour of {name}": "更改 {name} 的颜色",
+  "Name of {name}": "{name} 的名称",
+  "Colour of the next shape": "下一个形状的颜色",
+  "Drawn shapes": "已绘制的形状",
   "Primary": "主题色",
   "Amber": "琥珀色",
   "Cyan": "青色",