Adding a node while hovering over an area fill causes a stack trace

[Bonkles]

While debugging the 'navigation' step of the walkthrough, I see we are now able to click the 'add point' button and click on a building interior fill. This is an improvement over before, where we simply weren't allowed to click on the fill (the click wasn't honored).

Now, though, the 'add node' mode thinks we're clicking ON THE WAY and so that we need to add a midpoint to the way- this is absolutely not the case.

Stack trace:

Uncaught TypeError TypeError: Cannot read properties of undefined (reading 'id')
    at <anonymous> (/Users/clarkben/working/RapiD/modules/actions/add_midpoint.js:10:54)
    at _act (/Users/clarkben/working/RapiD/modules/core/history.js:43:29)
    at _perform (/Users/clarkben/working/RapiD/modules/core/history.js:61:28)
    at perform (/Users/clarkben/working/RapiD/modules/core/history.js:220:24)
    at <anonymous> (/Users/clarkben/working/RapiD/modules/core/context.js:318:25)
    at _clickWay (/Users/clarkben/working/RapiD/modules/modes/ModeAddPoint.js:135:18)
    at _click (/Users/clarkben/working/RapiD/modules/modes/ModeAddPoint.js:107:14)
    at emit (/Users/clarkben/working/RapiD/node_modules/eventemitter3/index.js:181:35)
    at _doClick (/Users/clarkben/working/RapiD/modules/behaviors/BehaviorDraw.js:303:10)
    at _pointerup (/Users/clarkben/working/RapiD/modules/behaviors/BehaviorDraw.js:213:12)
    at emit (/Users/clarkben/working/RapiD/node_modules/eventemitter3/index.js:202:33)
    at _pointerup (/Users/clarkben/working/RapiD/modules/pixi/PixiEvents.js:242:10)
    at notifyListeners (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventBoundary.ts:1313:26)
    at notifyTarget (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventBoundary.ts:545:14)
    at propagate (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventBoundary.ts:336:18)
    at dispatchEvent (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventBoundary.ts:240:14)
    at mapPointerUp (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventBoundary.ts:830:14)
    at mapEvent (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventBoundary.ts:261:28)
    at onPointerUp (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventSystem.ts:290:31)

[Bonkles]

Fixed in 334140e524a1010b2bf49970eaeb844c211b8ca5. If a fill is being hovered, don't treat it like a snap and instead treat it like a click on an empty section of the map.