Let user select a version a `runtimeExecutable` path to specific node.js in Node Launch Configuration

WWD needs a NodeJS to run language servers, and also to execute NodeJS launch configurations. Currently, there's not much control over which NodeJS is used. You either have to set org.eclipse.wildwebdeveloper.nodeJSLocation in eclipse.ini or add NodeJS to your PATH. This isn't very flexible, and is problematic because I work on multiple projects that use different versions of NodeJS.

Today, I'm just setting nodeJSLocation and living with the fact that language servers are run with a different NodeJS than the projects are built with. And I'm using JSDT's NodeJS launch config to build the projects, since JSDT allows me to select which NodeJS I want.

It would be nice if WWD provided a workspace-level config option to set which NodeJS to use, and used the specified NodeJS to start language servers and to run NodeJS launch configs.

首先跟踪现有的 org.eclipse.wildwebdeveloper.nodeJSLocation 设置、语言服务器启动过程以及 NodeJS 启动配置。完成的标准是，工作区级别的 Node.js 选择同时对语言服务器和 NodeJS 启动配置生效，包括使用不同 Node.js 版本的项目。