Added experimental generation of G

CHANGELOG.md

api/core/data/management.py

api/core/data/processing/common.py

api/core/data/processing/filling.py

api/core/data/processing/flagging.py

api/core/data/processing/importing.py

api/core/eea/generate_attainment/directives/alt.py

api/core/eea/generate_attainment/directives/cl.py

api/core/eea/generate_attainment/directives/common.py

api/core/eea/generate_attainment/directives/eco.py

api/core/eea/generate_attainment/directives/ert.py

api/core/eea/generate_attainment/directives/int.py

api/core/eea/generate_attainment/directives/limitvalues.py

api/core/eea/generate_attainment/directives/lto.py

api/core/eea/generate_attainment/directives/lv.py

api/core/eea/generate_attainment/directives/tv.py

api/core/eea/generate_attainment/g.py

api/endpoints/management/attainments/models.py

api/endpoints/management/attainments/routes.py

client/src/components/Confirm.vue