[Integrations] Add slug field to mongoDB embalses

[brauliodiez]

Let's add a field slug name right now we will use the "nombre" field but replacing blanks spaces with dashed, and "tilde" with standard letter, and no uppercase.

e.g.

Arcos de la Frontera --> arcos-de-la-frontera

Celemín --> celemin

Additional we should add the province name but this is not implemented on the integrations.