libgda 5.2.10
 - MySQL: initial support for JSON type
 - MySQL: test against 8.0
 - GdaParser: remove spaces and enters before next statement, fix 203
 - GdauiSet: fix gdaui_set_source_get_ref_columns() return value, fix #123
 - SqlParser: fix Vala bindings
 - Vala: added missing variadic methods to VAPI
 - Removing Python 2 support to use Python 3 by default
 - Glade catalog and pixmaps installation directory fixed for make distcheck