Fix the Triage Summary view's exports list to only update when visible

The `ExportsTreeView` now asks the model to pause / resume updates when
its visibility changes. When paused, all notifications from the view are
ignored. When resumed, notifications set a flag to indicate that an
update is needed and resume the update timer if it is not already
active. The timer is stopped after an update is processed.

There's some extra complexity here to avoid emitting a signal for every
`BinaryView` notification that is processed. These notifications are
typically generated on background threads. The overhead of emitting a
signal and it being routed to the main thread adds up given the number
of notifications involved when loading a large binary.

0 files changed, 0 insertions, 0 deletions