Handle http errors of create episode request

[gazdagergo]

When sending graphql mutation POST request to hygraph, we have to handle the "non-happy" path as well. If the creation of the new episode was unsuccessful for some reason

• we have to log it into the db (adding a new field first for errors)
• we have to keep the txt file instead of removing

To achieve this we have to bubble up the error and do not let the scheduler run the upcoming commands. We have to move the filne into en "error" subfolder of the output folder to avoid re-triggering the transcript processing.