WebGLRenderer: review start_rendering() and stop_rendering() methods

[vatro]

Should work as expected, but I did't test them enough (use cases). Test functionality and nail down usage.

svelthree/src/components/WebGLRenderer.svelte

Lines 759 to 772 in 8fb54d2

	// TODO this has to be tested / used / optimized (_isn't used in any of the test scenes up to date_)
	/** Cancel any scheduled `requestAnimationFrame` and disable further rendering. */
	export function stop_rendering(): void {
	enabled = false
	cancelAnimationFrame(rAF.id)
	render_scheduled.status = false
	}
	// TODO this has to be tested / used / optimized (_isn't used in any of the test scenes up to date_)
	/** Cancel any scheduled `requestAnimationFrame` and disable further rendering. */
	export function start_rendering(): void {
	enabled = true
	start_renderer()
	}