Add xml info to pdf metadata2 (#15)

Add xml info to pdf metadata2 (#15)

* Bump to 2.3.0

* PR #7 Include XML information in PDF metadata (cmcproject)

* update mustang validator

* fixes fx:DocumentFileName / fx:DocumentType order

* remove `schemas/ZUGFeRD2p2_extension_schema.xmp` (replaced by `xmp_schema.py` generator)

* removes date and seller from pdf metadata subject to simplify the code and remove hard coded English language

* removes doc type date and seller from pdf metadata subject (incl. the restriction to documents of type 380) to simplify the code and remove hard coded English language

* remove unused (now) unused constant INVOICE_TYPE_CODE and avoid the use of use bare `except`

* removes failing "Invalid doc type! XML value for TypeCode shall be 380 for an invoice." test

* allows to supply explicit profile level and extends profile auto detection to cover XRECHNUNG

* minor code style improvements like lazy % formatting in logging functions (logging-fstring-interpolation)

* fixes style (black)

* tests of auto detecting a XRechnung v2 and v3 profiles

* blacking again

* tests for en16931 auto profile recognition and auto profile recognition failure

* black again

* typo

* allow users to set custom pdf metadata and the PDF language identifier used by PDF readers for blind people

* black

* spelling

* Update drafthorse/pdf.py

* Run black

---------

Co-authored-by: Raphael Michel <michel@rami.io>
Co-authored-by: Raphael Michel <mail@raphaelmichel.de>