feat(debugger): Show the value of the selected code while paused (#173)

Settings › Debugger › Data Views gains Show value tooltip on code selection
(on by default). While the debugger is paused, selecting an expression on one
line shows its value once the selection settles, with objects expandable like
the hover tooltip.

src/features/settings/pages/execution.tsx

@@ -180,6 +180,7 @@ export const EXECUTION_PAGES: PageSpec[] = [
             label: "Show value tooltip on mouse hover",
             hint: "Hovering a variable while suspended evaluates it in the selected frame.",
           },
+          { kind: "toggle", key: "debugger.valueTooltipOnSelection", label: "Show value tooltip on code selection" },
           { kind: "custom", label: "Value tooltip delay (ms)", component: TooltipDelayRow },
         ],
       },