Loading indicator for loading the tree. Tree displays PK, FK, R, and U.
Still some bugs with the connections and I want to implement a
"connection manager" which the ability to change, edit, and delete
connections. PLUS right now the tree view is only supported for PSQL.
Need to use different queries for different SQL types. SOME types, like
SQLlite, might not support the tree, and I will need a display for that.
Plus errors are not handled, just bubbled and logged :|
