Fix pseuCoUrlFileEncoders only supporting files whose contents are strings

The RemoteFile type was too restrictive to be correct. I changed it locally, only in util/pseuCoUrlFileEncoder.ts, oblivious if this is a breaking change.

Additionally, when parsing, we need to be aware if we are handling a textfile (lts, ccs) or an object. In the latter case, we need to parse the 'text' at hand yet again.