Clear functionality in DOMRenderer

[oscarlorentzon]

It should be possible for a DOMUI to clear its hash and therefore its content in the virtual DOM with an method on the DOMRenderer similar to the functionality in the GLRenderer:

mapillary-js/src/render/GLRenderer.ts

Lines 308 to 310 in ea9e928

	public clear(name: string): void {
	return this._clear$.onNext(name);
	}

mapillary-js/src/render/GLRenderer.ts

Lines 132 to 140 in ea9e928

	this._clear$
	.map<IGLRenderHashesOperation>((name: string) => {
	return (hashes: IGLRenderHashes): IGLRenderHashes => {
	delete hashes[name];
	return hashes;
	};
	})
	.subscribe(this._renderOperation$);

DOMUIs should clear their hash (and release potential memory) on deactivation.

[gyllen]

I have a patch for this. Just missed to push.

[gyllen]

Added patch