typestring has been updated and now throws a bunch of diagnostics instead of just one

Typestring has been updated and now throws an [array of diagnostics](https://github.com/gavinhungry/typestring/blob/master/typestring.js#L48-L51) instead of just a single error. This pr handles that as follows:
- multiple Pluginerrors are emitted, 1 for each 'diagnostic'.
- the diagnostic object contains all the context info about the error. I've used it to pass thru the line number where the error occurs.