…age and improve table handling

…it tests

…nd add origin metadata in PDFExtractor

- Added new file types (MD, ASCIIDOC, CSV, TXT, IMAGE) to FileType enum.
- Refactored test cases to utilize new _FakeTable and _FakeDataFrame classes.
- Updated document extractor Dockerfile to include libleptonica-dev and pkg-config.
- Upgraded docling package to version 2.61.2 and added tesserocr as a dependency.
- Improved document upload component to dynamically display allowed file types.
- Localized upload descriptions to include allowed file types in both English and German.
- Introduced utility functions for document type validation, including MIME type and file extension checks.
- Added unit tests for document type validation logic.

…loadContainer

- Created a plain text sample file with multiple lines.
- Added a sample Excel file with a significant amount of data.
- Introduced an XML sample file containing a title and a paragraph.

…error handling

- Added module docstrings to various Python files for better clarity and maintainability.
- Improved function docstrings to provide detailed parameter and return information.
- Updated `flake8` and `pydocstyle` dependencies to ensure code quality checks are in place.
- Bumped version numbers for `admin-backend`, `document-extractor`, `mcp-server`, and `rag-backend` to 3.3.0.
- Added new dependencies for `flake8-docstrings` and `flake8-logging-format` to enhance linting capabilities.
- Cleaned up unnecessary whitespace and comments in test files.

…cies

…ests

…date TesseractImageExtractor's PSM default value

…cling_extractor_test

…ous extractors

…nce test coverage

…ctor pipeline details

… templates and clear existing tags in values.yaml