[browser/filters] Add FileExtension and MimeType Filters

Add FileExtension and MimeType Filters

Introduce two new filters, FileExtension and MimeType, to enhance file processing capabilities and MIME type validation.

FileExtension Filter:

• Extracts file extensions from file names or paths.
• Supports optional validation of associated MIME types.
• Improved handling of inputs without dots or with multiple dots.

MimeType Filter:

• Retrieves MIME types from file names, paths, or extensions.
• Enhances error handling for unrecognized MIME types.
• Can be used to validate MIME types associated with FileExtension.

        MimeType
        """
        Get the MIME type from a file name or path.

        :param txt: The file name or path for which to determine the MIME type.
        :type txt: str
        :raises FormatError: If the MIME type is not recognized.

        >>> MimeType().filter('foo.pdf')
        'application/pdf'
        >>> MimeType().filter('path/foo/invoices.tar.gz')
        'application/x-tar'
        >>> MimeType(default='NAN').filter('foo.no')
        'NAN'
        """
        FileExtension
        """
        Get the file extension from a file name or path.

        :param txt: The file name or path for which to extract the file extension.
        :type txt: str
        :raises FormatError: If the file extension is not recognized.

        >>> FileExtension().filter('file.docx')
        'docx'
        >>> FileExtension().filter('path/to/file.tar.gz')
        'tar.gz'
        >>> FileExtension(default='NAN').filter('file_without_extension')
        'NAN'
        >>> FileExtension().filter('/home/user/Documents/report.pdf')
        'pdf'
        >>> FileExtension(default='UNKNOWN').filter('spreadsheet')
        'UNKNOWN'
        >>> FileExtension(default='UNKNOWN', validate_mime=True).filter('path/to/file.dfs')
        'UNKNOWN'
        >>> FileExtension(default='UNKNOWN', validate_mime=True).filter('file.jpg')
        'jpg'
        """

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