Dynamic install puppet implementations instead of pre-install

[huan]

In order to support WECHATY_PUPPET=xxx environment, we need to be able to load the specific puppet at runtime.

Currently, we pre-installed PuppetPadchat, PuppetPuppeteer, PuppetWechat4u, PuppetMock to import into our puppet-config.ts.

However, sometimes it's unnecessary to install all of them because we only use one or two of them.

So it will be better to install them when be required.

I believe NPM should be programmed to do this job.

To Be Investigated.

[huan]

Done.