runtime: better errors for implicit globals

This code:

for (collection of collectGroupArray) { }

Produces an error like this:

R/T SyntaxError: The requested module '@openfn/language-mssql' does not provide an export named 'collection'

collection is an implicit global variable. The compiler generates an import statement, assuming that it will be provided by the adaptor.

But it is not provided by the adaptor! It's a global defined by the code!

The error we get is incomprehensible to users

What can we do?

• We could try to detect that collection is not a valid import and throw a clearer error earlier
• We could detect SyntaxErrors of this form/pattern, and add some diagnostic information like "this can happen if you assign to a global variable)

Reproduce the example with for (collection of collectGroupArray) { } and trace how the compiler-generated import reaches the runtime. Compare the resulting SyntaxError with the intended implicit-global diagnostic; done means the failure is identified earlier or explained with actionable diagnostic information.