Add layerGroups to the map for the user to be able to filter
along the different cells (Department, cities, 10km, 1km)
Added id_type to all queries to be able to filter along this
property

Correct zoom function to work on all "fiches" by adding a
zoomMaille function
Added snogylop to ficheCommune.html and invert: true in style of
map
Changed layerGroup by featureGroup to have bringToBack and
bringToFront functions
Add bringToFront and bringToBack to respectively the 1km² cell and
the department because it was impossible to click on a city cell

Changed the sql files to be able to reproduce the changes done on
the database.

Tested if it was possible to add hover and click effect to
hightlight a specific cell.
Added ZIndex values for the filter to be more robust

Beforehand the lastObservationsCommuneMaille selected from
the vm_observations which was not coherent. Now it selects from
vm_observations_mailles.
Add columns to select and removed the last_obs intermediate
Enabled to get the id of the cell and its type.

Cells border color is now grey
Made styleMailleClickedOrHover more versatile
styleMailleClickedOrHover now takes the --main-color css var to
fill the cells with the main color of the atlas
Removed setZIndex because it was useless

Added a new var (main-color-rgb) which is the same as main-color
variable but with a rgb description enabling to set different
opacity depending on the state (hover or click) of the row in
the tabEspece

Now the layers stack properly when the user activate or deactivate
them from the Control (top hand right corner).
Add a selected variable enabling the clicked cell to stay filled
even if the mouse exits the cell (mouseout event called)

Before was used to find a way to set background opacity other
than by using rgb formulation

Sql query was from vm_observations whereas we are in
a Maille function so it should be from vm_observations_maille
Corrected a copy paste mistake on id_type
Added dateobs in lastObservationsCommune

The older function took oservations based on Insee whereas it
should take info from the observations requested before. This new
function is based on the observations dictionnary that is
computed from the vm_observations (maille or not) and take the
taxons info
Used this function in atlasRoutes.py

mapHome.js: Clarified code
mapGenerator.js: Move control layer bloc for  more clarity as well
  Added id_type in property for geojson of commune
  Corrected a bug by added addTo(map) in displayMailleLayerLastObs
mapHome.js: simplified code

To be compatible with the new get_taxons_from_obs function, the
date object must be returned and not an str conversion

The function crashed when there were no taxons in a particular
city. Changed also the request for it to be more versatile in
terms of cd_ref (bugged when there was one taxon)

atlas.sql:
   add centroid to vm_observations to be compatible with point
   mode
   Changed st_contains by st_intersect as mentionned in an issue
observations_mailles.sql:
   Changed tables where to take infos
   Make this vm independant from vm_observations
   Removed index since it take to much space
atlas_synthese.sql:
   Changed index since it was not working with observations that
   do not have type_code
   Returns Point when there is no sensibility instead of a mesh
   cell

Need to update leaflet for bringToFront/BringToBack to work
Remove dependency to snogilop (had to test for compatibility)

To be able to alter the background transparency of the species
list on the main page, we need to have a rgb color. Indeed rgba()
css function does not work on hexadecimal colors. It adds complexity
but this seems to be the only way

In FicheEspece: the displayed cities were not right. There was no
instersection between the observation and the cities. Now for
instance, for a department level observation all the cities in the
department will appear...

In popup showing species, removes duplicates so that only different
species are displayed

Changed the plain id number to a Select with a Like to enter
directly the mesh cell type
It might be a parameter in the settings.ini in the future