The payload might contain colons and commas within keys and
values entered by the user. Simply splitting the fields using
", " is therefore unreliable and can lead to incorrect parsing.
Hence, this commit updates the logic for splitting fields in
the pretty data of the Jotform payload.
Fixes#32461.
Since FIXTURE_DIR_NAME is the name of the folder that contains the view
and tests modules of the webhook and another folder called "fixtures" that
store the fixtures, it is more appropriate to call it WEBHOOK_DIR_NAME,
especially when we want to refer to the view module using this variable.
