ux: reverse order in which exceptions are reported (vyperlang#2838)

this commit reverses the order in which multiple exceptions are
reported. this is a usability issue because sometimes when exceptions
cascade, the first error is the most meaningful (other errors depend on
the first error being fixed).

vyper/exceptions.py

@@ -18,7 +18,7 @@ def raise_if_not_empty(self):
             raise self[0]
         elif len(self) > 1:
             err_msg = ["Compilation failed with the following errors:"]
-            err_msg += [f"{type(i).__name__}: {i}" for i in self]
+            err_msg += [f"{type(i).__name__}: {i}" for i in reversed(self)]
             raise VyperException("\n\n".join(err_msg))