Tools: automatically generate exports from common

The current pattern in adaptors is for an adaptor to export a list of useful functions from common for use in job writing code.

Most adaptors include a link like this at the bottom:

export {
  field,
  fields,
  sourceValue,
  alterState,
  fn,
  each,
  merge,
  dataPath,
  dataValue,
  lastReferenceValue,
} from '@openfn/language-common';

There are a couple of problems with this:

• It's tedious
• It's brittle
• How do you know you're exposing the right functions?
• Users creating new adaptors will basically never touch these exports

I think we should be able to auto-generate this function list as part of the build process - so that adaptor source does not export from common, but the build inserts an export list. This would have to be smart and only expose functions which are not also exported by the adaptor itself.

Start by reviewing the repeated adaptor export blocks and tracing the build process that handles adaptor source. Define how generated exports should include common functions while excluding names exported by each adaptor, then verify that adaptor source no longer needs to maintain these lists.