Add closeOnExcept to clean up code that closes resources only on exceptions

[jlowe]

I've been bumping into a number of cases where a resource is obtained, some computation needs to happen on that resource, then ownership of the resource is handed off to somewhere else. During the computation it's important to cover the exception path, which means writing code that looks something like this:

val r = ...some code that obtains a resource...
try {
  ...some code that computes on the resource...
} catch {
  case t: Throwable =>
    r.safeClose()
    throw t
}

The withResource code is a nice wrapper for handling the case where a resource must always be closed, but we don't have something to cover the case where a resource should only be closed if an exception occurs.

This PR adds closeOnExcept methods that are similar to withResource but closing in a catch clause rather than a finally block. It also updates code that was using this code pattern.

[jlowe]

build

[revans2]

The changes look fine but could you please sign your commit like we are asking others to do.

[jlowe]

build

[jlowe]

We need the fix from #461 or to turn off the noscaladoc rule before the CI build is going to pass.

[abellina]

build