Add Codesandbox metrics to usage ping
We should find out frequently the Codesandbox live preview in the Web IDE is used.
### Proposal
There are several different metrics we should look at here:
1. How many instances have Codesandbox enabled? - We could do this today even without have the self-hosted version as instances are able turn this feature on.
2. How many Web IDE instances use this feature? - This should be based on the number of times the live preview pane is accessed.
### Links / references
issue