update sidebar.js - check for tree's city

[emillipede]

to integrate data from other cities, some parts of the sidebar need to be city-specific (eg certain fields for certain cities)

for now, the sidebar will appear one way for trees in santa monica, and another way for trees outside of santa monica.

some santa monica-specific features, like "report tree" and the heritage field, aren't applicable for other cities. some other cities may have their own idiosyncrasies.