Incorrect site type icons for Canopeum and Farms Land

[Samuel-Therrien-Beslogic]

As mentioned in #270 and #271:

https://www.npmjs.com/package/material-icons does not support custom icons.
Since we already use https://www.npmjs.com/package/@mui/material, we could consider https://www.npmjs.com/package/@mui/icons-material .

For the short term, we're using incorrect, but still unique, icons for "Canopeum" and "Farms Land".

We need to be able to use custom icons for those two site type. Preferably by registering svgs as icons to work with the rest of the system. But if we really have to, a custom higher-order component for rendering site type icons may do.

Similarly, the map pins would be preferable as generic pins that can take any icon

(see the linked PRs for code location)