Grouping LegalProvisions GEO-2555

[marionb]

The aim of this PR is to:

• in the configuration: a new parameter "group_legal_provision" which activate the grouping logic if the parameter is set to "true". The parameter is set to false per default
• if grouping logic is active, then the list elements "LegalProvision" with the same "Title.Text" are grouped in the resulting PDF

Implements #819

For testing set group_legal_provisions to true

[pfirpfel]

Here is an overview of what got changed by this pull request:

Complexity increasing per file
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- pyramid_oereb/contrib/print_proxy/mapfish_print.py  3
         

See the complete overview on Codacy