Check didn't flag extra pipe characters in custom typed relation field

[dara2]

I am in Drupal 9.3.3, running the latest Workbench from my local.
I have a site with a custom typed relation field. The CSV passed the --check process, but when I started to ingest, it failed with this error:

Traceback (most recent call last):
  File "./workbench", line 1130, in <module>
    create()
  File "./workbench", line 257, in create
    subvalues = split_typed_relation_string(config, row[custom_field], target_type)
  File "/home/islandora/islandora_workbench/workbench_utils.py", line 1601, in split_typed_relation_string
    if value_is_numeric(item_list[2]):
IndexError: list index out of range

When I looked at my CSV I saw the node that it was trying to ingest had data in the custom typed relation field like this, with an extra leading pipe character:

|local:dgc:person:Paschen, Elise|local:dgc:person:McManus, James

The --check had caught a similar issue in the Linked Agent typed relation field, but for some reason didn't catch this. When I looked in the rest of the CSV, there are several other places where this happens in this same custom field, none of which --check apparently caught. It would be helpful if --check caught this.

[mjordan]

Note to MJ: All CSV field types should be checked for superfluous subdelimiter characters, not just typed relation fields.

[mjordan]

This could be added to clean_csv_values().

[mjordan]

@dara2 sorry this took so long! Anyway, now all trailing and leading subdelimiter characters should be stripped from CSV values.