Cleanup Ballerina Central and split it into Production and Test

[tj800x]

There are a bunch of junk modules in Ballerina Central. For someone evaluating the platform it projects an image of low quality.

By my count there are at least 25 Hello World projects, not including pre 1.0 packages:
https://central.ballerina.io/search?q=Hello%20world

[tj800x]

I removed my suggested fix as there are probably plenty of ways to fix this.

[hemikak]

Thanks @tj800x , we will look into this matter.

[anupama-pathirage]

Closing this issue as it is tracked via #20938