WMS integration in front-end

[sirmmo]

The structure of the front-end revealed some complex issues to manage the WMS visualization, as the previous developers used an unmaintainable way to display the data. The culprit for many of the issues is the setupFrontLayer code, visilble here: https://github.com/venetoarpa/Arpav-PPCV/blob/c9bdd0eaf3f6e2d150ed9623d50501c9cc6a05ef/src/app/components/Map/ThreddsWrapperLayer.tsx#L25-L58

This method does not set up the front layer "per se", but decides based on a series of operations that the same layer could be deleted while being added.