Dont create a fragment at all for DOM-less component

[tanhauhau]

Fix #2200

[Rich-Harris]

Ah yes, this is great — will shrink down my Svelte GL apps nicely 🍻

[mustafa0x]

	has_content() {
		const chunks = ['intro', 'outro', 'create', 'hydrate', 'claim', 'mount', 'update', 'destroy'];
		return this.renderer.options.dev ||
			this.first ||
			this.event_listeners.length > 0 ||
			chunks.some(k => this.chunks[k].length > 0) ||
			this.has_animation;
	}