Feature: Allow setting backend configuration settings via the UI (#5126)

* Saving some start on this

* At least partially working for the tesseract parser

* Problems with migration testing need to figure out

* Work around that error

* Fixes max m_pixels

* Moving the settings to main paperless application

* Starting some consumer options

* More fixes and work

* Fixes these last tests

* Fix max_length on OcrSettings.mode field

* Fix all fields on Common & Ocr settings serializers

* Umbrellla config view

* Revert "Umbrellla config view"

This reverts commit fbaf9f4be30f89afeb509099180158a3406416a5.

* Updates to use a single configuration object for all settings

* Squashed commit of the following:

commit 8a0a49dd57
Author: shamoon <4887959+shamoon@users.noreply.github.com>
Date:   Tue Dec 19 23:02:47 2023 -0800

    Fix formatting

commit 66b2d90c50
Author: shamoon <4887959+shamoon@users.noreply.github.com>
Date:   Tue Dec 19 22:36:35 2023 -0800

    Refactor frontend data models

commit 5723bd8dd8
Author: Adam Bogdał <adam@bogdal.pl>
Date:   Wed Dec 20 01:17:43 2023 +0100

    Fix: speed up admin panel for installs with a large number of documents (#5052)

commit 9b08ce1761
Author: shamoon <4887959+shamoon@users.noreply.github.com>
Date:   Tue Dec 19 15:18:51 2023 -0800

    Update PULL_REQUEST_TEMPLATE.md

commit a6248bec2d
Author: shamoon <4887959+shamoon@users.noreply.github.com>
Date:   Tue Dec 19 15:02:05 2023 -0800

    Chore: Update Angular to v17 (#4980)

commit b1f6f52486
Author: shamoon <4887959+shamoon@users.noreply.github.com>
Date:   Tue Dec 19 13:53:56 2023 -0800

    Fix: Dont allow null custom_fields property via API (#5063)

commit 638d9970fd
Author: shamoon <4887959+shamoon@users.noreply.github.com>
Date:   Tue Dec 19 13:43:50 2023 -0800

    Enhancement: symmetric document links (#4907)

commit 5e8de4c1da
Author: shamoon <4887959+shamoon@users.noreply.github.com>
Date:   Tue Dec 19 12:45:04 2023 -0800

    Enhancement: shared icon & shared by me filter (#4859)

commit 088bad9030
Author: Trenton H <797416+stumpylog@users.noreply.github.com>
Date:   Tue Dec 19 12:04:03 2023 -0800

    Bulk updates all the backend libraries (#5061)

* Saving some work on frontend config

* Very basic but dynamically-generated config form

* Saving work on slightly less ugly frontend config

* JSON validation for user_args field

* Fully dynamic config form

* Adds in some additional validators for a nicer error message

* Cleaning up the testing and coverage more

* Reverts unintentional change

* Adds documentation about the settings and the precedence

* Couple more commenting and style fixes

---------

Co-authored-by: shamoon <4887959+shamoon@users.noreply.github.com>

src/documents/parsers.py

@@ -125,8 +125,10 @@ def get_parser_class_for_mime_type(mime_type: str) -> Optional[type["DocumentPar
     if not options:
         return None
 
+    best_parser = sorted(options, key=lambda _: _["weight"], reverse=True)[0]
+
     # Return the parser with the highest weight.
-    return sorted(options, key=lambda _: _["weight"], reverse=True)[0]["parser"]
+    return best_parser["parser"]
 
 
 def run_convert(
@@ -318,6 +320,7 @@ class DocumentParser(LoggingMixin):
     def __init__(self, logging_group, progress_callback=None):
         super().__init__()
         self.logging_group = logging_group
+        self.settings = self.get_settings()
         os.makedirs(settings.SCRATCH_DIR, exist_ok=True)
         self.tempdir = tempfile.mkdtemp(prefix="paperless-", dir=settings.SCRATCH_DIR)
 
@@ -330,6 +333,12 @@ class DocumentParser(LoggingMixin):
         if self.progress_callback:
             self.progress_callback(current_progress, max_progress)
 
+    def get_settings(self):  # pragma: no cover
+        """
+        A parser must implement this
+        """
+        raise NotImplementedError
+
     def read_file_handle_unicode_errors(self, filepath: Path) -> str:
         """
         Helper utility for reading from a file, and handling a problem with its