SELECT * FROM * no longer allowed in subscriptions

[gefjon]

Errors with Unsupported query on subscription: "Multiple statements in subscription query".

Should also add a test to the SDK tests which exercises this.

[gefjon]

Likely the path of least resistance here is, instead of recognizing SELECT * FROM * in the SQL compiler, detecting it earlier when parsing the Subscribe message and invoking a separate compilation path.

[joshua-spacetime]

I know we need to support this for the time being, but we should probably reconsider whether we want to support it for 1.0. It's a useful utility, but technically it's not valid SQL.

[gefjon]

I added a test for this to the branch phoebe/select-star-broken, but am now going to do by very best to find someone who isn't me to fix it.

[Centril]

cc #1220