Improve BPE flow diagram and gf Python code

[ThomasPO]

BPE flow diagram

• add code lists generation to bpe flow diagram
• redesign of the BPE workflow diagram

Python code

• feat: add write code list files on ftp and fix: CSVW generation and code list generation
  • add csv files describing variables for french facilities
  • apply filtering of facilities to metadata extracted
  • add json serialization for csvw python dictionary and load to ftp
  • add metadata transformation to csvw python dictionary
  • add second metadata file extracted
• recode variable QUALITE_XY
• add second data file extracted and add a concatenate task
• switch int type to Int64 and use of dtype for extracting data + add filter for selecting Exhibition places and heritage

CSVW: population-sample.csv-metadata.json

• add title, description and creator to the root and change name for nuts3 references