lila should not be catching general Exceptions

[isaacl]

As exemplified by impl of scala.util.Try, our try catches should not be catching general Exception class. This includes InterruptedException which it's unlikely we want to suppress.

We should replace instances of catch case e: Exception => with

catch case scala.util.control.NonFatal(e) =>

or a more specific exception if available.

[lenguyenthanh]

Agree, another option in our hands is Either.catchNonFatal.