[FEAT](Map at country-level) Layers selectors

[charlottegiseleweil]

Environmental layers

-> layers listed in issue #20

Reef layers

-> layers from #16

Environmental clusters

-> layers from #18

Sampling sites

-> Points from expedition (2022, 2023)
Dropdown for selecting point coloring :

• option 1: "hard coral cover" (by default), described in [FEATURE] Classify expeditions (the marker) in color by the coral condition #8
• option 2 : "by year"
• option 3 :by project

Related features:

• Legend should update automatically,
• Source and attributions update automatically