Feature: store barcode contents, list and search them (#14276)

* Feature: store barcode contents, list and search them

New setting PAPERLESS_CONSUMER_STORE_BARCODE_VALUES (off by default)
stores all barcodes found during consumption with the document: page,
type and content. They are listed on the metadata tab with a copy
button, returned by the documents API and searchable with barcodes:
in the advanced search. Versions keep their own barcodes, reprocessing
reads them again. Refs #9898

* Tests: cover the remaining barcode branches

Covers unchanged and failing barcode reads on reprocessing, unsupported files and DocumentBarcode.__str__, and uses toHaveLength in the barcode list spec as suggested by SonarCloud.

* Address review: keep barcodes when they can't be read, format choices

- Reprocessing and new versions keep the stored barcodes when the file
  can't be scanned or the scan fails, and replace them atomically.
- Format is a TextChoices of the zxing-cpp formats, with a test.
- Shared scan code, latest_version helper, TypedDict, serializer reuse.
- Barcodes in the split manifest, export/import tests, pytest-style tests.

* Barcode tests: TIFF reprocess, format check both ways, fixtures

- Reprocessing a TIFF with TIFF support off keeps the stored barcodes.
- The format test also fails when zxing-cpp drops a format.
- Fixtures in place of the sample dir mixin, plugin-level disabled test.
- Format labels aren't translated, OpenAPI enum named BarcodeFormatEnum.

* Review: module-level zxing reader, shorter barcode docs

- read_barcodes_zxing is a module-level function used by scan_pdf.
- Drop the trivial __str__ test, mark it no cover.
- Shorten the barcode docs and remove the duplicate in configuration.md.

* Fix header

* Use utility class

* Return barcodes from the metadata endpoint only

Drop the barcodes field and its prefetches from the document serializer,
as agreed in the review. Also remove the now empty component stylesheet.

---------

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

docs/advanced_usage.md

@@ -1010,6 +1010,19 @@ documents to both separate and categorize them in a single operation.
 **Example:** A 6-page scan with TAG:invoice on page 3 and TAG:receipt on page 5 will create
 three documents: pages 1-2 (no tags), pages 3-4 (tagged "invoice"), and pages 5-6 (tagged "receipt").
 
+### Barcode Contents {#barcode-contents}
+
+By default, Paperless only uses barcodes for splitting, ASNs and tags. With
+[`PAPERLESS_CONSUMER_STORE_BARCODE_VALUES`](configuration.md#PAPERLESS_CONSUMER_STORE_BARCODE_VALUES)
+enabled, it stores the content of every barcode with the document, e.g. payment codes or QR codes.
+
+- Barcodes are listed on the **Metadata** tab with page, type and content, and can be copied.
+- The API returns them in the `barcodes` field of `/api/documents/{id}/metadata/`.
+- They can be [searched](usage.md#searching-barcodes), e.g. `barcodes:DE89370400440532013000`.
+- Only the first [`PAPERLESS_CONSUMER_BARCODE_MAX_PAGES`](configuration.md#PAPERLESS_CONSUMER_BARCODE_MAX_PAGES)
+  pages are scanned. Reprocessing reads the barcodes of existing documents.
+- Each version keeps its own barcodes, and the newest version's are shown and searched.
+
 ## Automatic collation of double-sided documents {#collate}
 
 !!! note