Adds VMA preprocessing tasks

[shelleydoljack]

Closes #1666

Cleans up some outdated code.
Adds tests for verifying data structure saved to VendorInterface record from form data.
Adds ability to prepend data to the 001 field.
Adds ability to add a subfield to an existing field, given a pattern match in the existing field's specified subfield, or simply add it to existing field regardless.

Vendor Interface view:

Vendor Interface edit view:

I didn't address the fact that the default_data_processor DAG has some hardcoded stuff in it (like remove fields 905, 920, 986 or add field 910 if data is entered in the package name). I also didn't add code to allow users to add a field (not sure if that is a desired feature).

[jermnelson]

This looks good!

[shelleydoljack]

Users have noticed an issue with clicking on vendor interfaces that have either an import profile linked to it and/or a file pattern. For example, when clicking on this interface:

The user gets an error page.
The log output shows this error:

[2026-01-06T21:42:02.560+0000] {app.py:1744} ERROR - Exception on /vendor_management/interfaces/152 [GET]
Traceback (most recent call last):
  File "/home/airflow/.local/lib/python3.11/site-packages/flask/app.py", line 2529, in wsgi_app
    response = self.full_dispatch_request()
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/airflow/.local/lib/python3.11/site-packages/flask/app.py", line 1825, in full_dispatch_request
    rv = self.handle_user_exception(e)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/airflow/.local/lib/python3.11/site-packages/flask/app.py", line 1823, in full_dispatch_request
    rv = self.dispatch_request()
         ^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/airflow/.local/lib/python3.11/site-packages/flask/app.py", line 1799, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/airflow/libsys_airflow/plugins/vendor_app/vendor_management.py", line 142, in interface
    return self.render_template(
           ^^^^^^^^^^^^^^^^^^^^^
  File "/home/airflow/.local/lib/python3.11/site-packages/flask_appbuilder/baseviews.py", line 342, in render_template
    return render_template(
           ^^^^^^^^^^^^^^^^
  File "/home/airflow/.local/lib/python3.11/site-packages/flask/templating.py", line 147, in render_template
    return _render(app, template, context)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/airflow/.local/lib/python3.11/site-packages/flask/templating.py", line 130, in _render
    rv = template.render(context)
         ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/airflow/.local/lib/python3.11/site-packages/jinja2/environment.py", line 1295, in render
    self.environment.handle_exception()
  File "/home/airflow/.local/lib/python3.11/site-packages/jinja2/environment.py", line 942, in handle_exception
    raise rewrite_traceback_stack(source=source)
  File "/opt/airflow/libsys_airflow/plugins/vendor_app/templates/vendors/interface.html", line 2, in top-level template code
    {% import "vendors/_macros.html" as _macros -%}
    ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/airflow/.local/lib/python3.11/site-packages/airflow/www/templates/airflow/main.html", line 21, in top-level template code
    {% from 'airflow/_messages.html' import show_message %}
    ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/airflow/.local/lib/python3.11/site-packages/flask_appbuilder/templates/appbuilder/baselayout.html", line 2, in top-level template code
    {% import 'appbuilder/baselib.html' as baselib %}
    ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/airflow/.local/lib/python3.11/site-packages/flask_appbuilder/templates/appbuilder/init.html", line 42, in top-level template code
    {% block body %}
  File "/home/airflow/.local/lib/python3.11/site-packages/flask_appbuilder/templates/appbuilder/baselayout.html", line 19, in block 'body'
    {% block content %}
  File "/opt/airflow/libsys_airflow/plugins/vendor_app/templates/vendors/interface.html", line 70, in block 'content'
    <dd class="processing_options">{{ interface.processing_options['prepend_001']['data'] }}</dd>
    ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/airflow/.local/lib/python3.11/site-packages/jinja2/environment.py", line 471, in getitem
    return obj[argument]
           ~~~^^^^^^^^^^
jinja2.exceptions.UndefinedError: 'dict object' has no attribute 'prepend_001'
172.28.0.1 - - [06/Jan/2026:21:42:02 +0000] "GET /vendor_management/interfaces/152 HTTP/1.1" 500 1592 "https://sul-libsys-airflow-stage.stanford.edu/vendor_management/vendors/5266" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.2 Safari/605.1.15"
172.28.0.1 - - [06/Jan/2026:21:42:02 +0000] "GET /favicon.ico HTTP/1.1" 404 456 "https://sul-libsys-airflow-stage.stanford.edu/vendor_management/interfaces/152" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.2 Safari/605.1.15"
127.0.0.1 - - [06/Jan/2026:21:42:07 +0000] "GET /health HTTP/1.1" 200 318 "-" "curl/7.88.1"

[shelleydoljack]

Fixed the issue with rendering interfaces that caused the error above with this commit