Extract to constant in enclosing scope should optionally also replace later usage

Given this code:

	public setParts(lineNumber: number, parts: GhostTextPart[]): void {
		const foreground = this.themeService.getColorTheme().getColor(ghostTextForeground);
		let opacity: string | undefined = undefined;
		let color: string | undefined = undefined;
		if (foreground) {


			opacity = String(foreground.rgba.a);
			color = Color.Format.CSS.format(opaque(foreground))!;
		}

		const borderColor = this.themeService.getColorTheme().getColor(ghostTextBorder);
		let border: string | undefined = undefined;
		if (borderColor) {
			border = `2px dashed ${borderColor}`;
		}

I would like to factor our this.themeService.getColorTheme() and extract it into its own constant. This should include all later usages.
Since there could be side effects in between, I suggest to do it only if later occurences are also selected.

This is my current workflow and I don't feel smart doing it like that. Multicursors don't really help here.

Also, it would be nice if the name of the new local is heuristically derived from the expression ((...).getFooBar(...) -> fooBar`).

I'm willing to do a PR if I get some pointers.

Let's make the editing experience in VS Code even more amazing 😉

Beginne damit, die Implementierung des Refactorings extract-to-constant und die dazugehörigen Tests im TypeScript-Repository zu finden. Reproduziere anschließend das gezeigte TypeScript-Beispiel und verfolge dann, wie Auswahlgrenzen und spätere Vorkommen behandelt werden. Als abgeschlossen gilt die Arbeit, wenn eine optionale Extraktion des umschließenden Gültigkeitsbereichs spätere Verwendungen nur dann einbeziehen kann, wenn sie ausgewählt wurden, wobei die heuristische Namensgebung separat betrachtet wird.