Add tracking for Angular projects

[teobugslayer]

It would be great to track the adoption level of NG2 and pure JS in NativeScript.

We are interested in two metrics:

• How much projects are created - i.e. tracking tns create --ng
• How much NG is used actively. In this case, the chosen performance metrics is this: when the user builds a project, check whether the project uses NG2.

These metrics should be tracked separately.