Revisit spoken form generation for decorated symbol mark

[pokey]

Decorated symbols are supposed to be editor-specific, but as of #1671, we handle spoken form generation in cursorless engine, which is supposed to be editor-agnostic. In particular, these two aspects are problematic:

• https://github.com/cursorless-dev/cursorless/blob/442f97d5d8787fadea300c6643ed0736a12c02f1/packages/cursorless-engine/src/generateSpokenForm/defaultSpokenForms/marks.ts

• cursorless/packages/cursorless-engine/src/generateSpokenForm/primitiveTargetToSpokenForm.ts

  Lines 220 to 231 in 442f97d

  	case "decoratedSymbol": {
  	const [color, shape] = mark.symbolColor.split("-");
  	const components: string[] = [];
  	if (color !== "default") {
  	components.push(hatColorToSpokenForm(color));
  	}
  	if (shape != null) {
  	components.push(hatShapeToSpokenForm(shape));
  	}
  	components.push(characterToSpokenForm(mark.character));
  	return components;
  	}

We should probably inject spoken form generator for this specific piece from the ide. Either that, or force the set of colors / shapes / symbols to be a subset of what we support in VSCode today and then keep doing evertying in engine. In that case, we'd want to switch to strong types everywhere for these

See also #946