Ability to estimate electricity usage footprint from a monetary amount

[corradio]

Requires #314

YAML configuration file containing the electricity retail prices that can be used.
Prepared by @martincollignon :

---
countries:
  BE:
    kWhPrice: 0.1948
    unit: EUR
    source: 'Eurostat, 2019'
  BG:
    kWhPrice: 0.0831
    unit: EUR
    source: 'Eurostat, 2019'
  CZ:
    kWhPrice: 0.1433
    unit: EUR
    source: 'Eurostat, 2019'
  DK:
    kWhPrice: 0.1084
    unit: EUR
    source: 'Eurostat, 2019'
  DE:
    kWhPrice: 0.1473
    unit: EUR
    source: 'Eurostat, 2019'
  EE:
    kWhPrice: 0.0982
    unit: EUR
    source: 'Eurostat, 2019'
  IE:
    kWhPrice: 0.2027
    unit: EUR
    source: 'Eurostat, 2019'
  GR:
    kWhPrice: 0.1139
    unit: EUR
    source: 'Eurostat, 2019'
  ES:
    kWhPrice: 0.1889
    unit: EUR
    source: 'Eurostat, 2019'
  FR:
    kWhPrice: 0.1138
    unit: EUR
    source: 'Eurostat, 2019'
  HR:
    kWhPrice: 0.1028
    unit: EUR
    source: 'Eurostat, 2019'
  IT:
    kWhPrice: 0.1432
    unit: EUR
    source: 'Eurostat, 2019'
  CY:
    kWhPrice: 0.1762
    unit: EUR
    source: 'Eurostat, 2019'
  LV:
    kWhPrice: 0.1136
    unit: EUR
    source: 'Eurostat, 2019'
  LT:
    kWhPrice: 0.0947
    unit: EUR
    source: 'Eurostat, 2019'
  LU:
    kWhPrice: 0.1326
    unit: EUR
    source: 'Eurostat, 2019'
  HU:
    kWhPrice: 0.0882
    unit: EUR
    source: 'Eurostat, 2019'
  MT:
    kWhPrice: 0.1228
    unit: EUR
    source: 'Eurostat, 2019'
  NL:
    kWhPrice: 0.1357
    unit: EUR
    source: 'Eurostat, 2019'
  AT:
    kWhPrice: 0.1316
    unit: EUR
    source: 'Eurostat, 2019'
  PL:
    kWhPrice: 0.0884
    unit: EUR
    source: 'Eurostat, 2019'
  PO:
    kWhPrice: 0.1101
    unit: EUR
    source: 'Eurostat, 2019'
  RO:
    kWhPrice: 0.0983
    unit: EUR
    source: 'Eurostat, 2019'
  SI:
    kWhPrice: 0.1125
    unit: EUR
    source: 'Eurostat, 2019'
  SK:
    kWhPrice: 0.0962
    unit: EUR
    source: 'Eurostat, 2019'
  FI:
    kWhPrice: 0.1173
    unit: EUR
    source: 'Eurostat, 2019'
  SE:
    kWhPrice: 0.1297
    unit: EUR
    source: 'Eurostat, 2019'
  UK:
    kWhPrice: 0.145
    unit: EUR
    source: 'Eurostat, 2019'
  IS:
    kWhPrice: 0.1112
    unit: EUR
    source: 'Eurostat, 2019'
  NO:
    kWhPrice: 0.136
    unit: EUR
    source: 'Eurostat, 2019'
  ME:
    kWhPrice: 0.0834
    unit: EUR
    source: 'Eurostat, 2019'
  MK:
    kWhPrice: 0.0664
    unit: EUR
    source: 'Eurostat, 2019'
  RS:
    kWhPrice: 0.0541
    unit: EUR
    source: 'Eurostat, 2019'
  TR:
    kWhPrice: 0.0684
    unit: EUR
    source: 'Eurostat, 2019'
  BA:
    kWhPrice: 0.0729
    unit: EUR
    source: 'Eurostat, 2019'
  XK:
    kWhPrice: 0.0537
    unit: EUR
    source: 'Eurostat, 2019'
  MD:
    kWhPrice: 0.0936
    unit: EUR
    source: 'Eurostat, 2019'
  UA:
    kWhPrice: 0.0369
    unit: EUR
    source: 'Eurostat, 2019'
  GE:
    kWhPrice: 0.0686
    unit: EUR
    source: 'Eurostat, 2019'