mod_map_select_server: Make a leaflet map with a reactive output
In ReseauBiodiversiteQuebec/mapselector: Map selector module for Shiny

This module is meant to help us make leaflet maps and output a reactive value. This value can be used to trigger a modal and also it's contents.

1	mod_map_select_server(id, what_to_click = "shape", fun = make_leaflet_map, ...)

`id`	this is the modal id string. It has to match the ui function. If you make a second map, use a different one
`what_to_click`	either "shape" for a region map or "marker" for a site map
`fun`	this is a function that makes a map; you might write this yourself or you might use one of the built in ones for sites (plot_rcoleo_sites) blank (make_leaflet_empty) or regions (make_leaflet_map)
`......`	additional arguments to fun