Allow to get bugreports using the diagnostics API

Allow to get bugreports using the diagnostics API

bugreport-service registers as a org.tizen.bugreport-service and allows
to get bugreport and crash-info report by dumpsys.
For example: to get all bugreports created in the last hour run:

  dumpsys org.tizen.bugreport-service -- --type bugreport --last 3600

Supported parameters:

  --type <bugreport|crash-info>  Get specified report
  --last <sec>          Get reports created in the last <sec>
  --from <timestamp>    Get reports created after a specified time
  --to <timestamp>      Get reports created before a specified time

Change-Id: I0d3e04c34b63f3a559c8bde9af703eeabeb4e7ae