Also make the poll interval configurable.
For the case of one targeter, the UI scans through the ActorTable to
find the relevant Actor, achieving either a partial or full scan. In
the case of more than one targeter, the UI constructs a Dictionary
mapping ActorId to Actor, then indexes that dictionary for each
targeter. This achieves one full scan, which may or may not be more
efficient than multiple partial scans, depending on where the actors
are located in the table.
The UI must do this because current targeters are no longer guaranteed
to be spawned anymore, especially with a high polling frequency, and
the UI needs accurate information about the targeters' address in
memory.