Generate setting Activity from maybe metadata

[xcv58]

We need a setting activity for debug or advanced users. It needs information of the package used maybe syntax.

It seems impossible in build process. So I think it's better we create a mechanism that can use data (retrieved from our backend) to dynamically generate the activity.

I don't know whether it's the best way to do this. But at least it's doable. So I think we need to think about:

1. UI, remember there're probably lots of maybe block/variable used in one package.
2. How to generate activity dynamic, any template we need.
3. How to handle no network connection (not able to retrieve data from backend).
4. Is there a better way to do this?