add `isinitialized(cam)` and optional wait reinit for `reset!`

[IanButterworth]

• Adds isinitialized(cam)
• Adds optional wait_reinit to reset! to wait after reset for a camera with the same serial number to appear and reconnect, overwriting cam with the new handle

julia> using Spinnaker

julia> camlist = CameraList()
CameraList with 1 enumerated devices:
ID  Serial No.  Description
0   xxx         FLIR Blackfly S BFS-U3-31S4M-BD

julia> cam = camlist[0]
FLIR Blackfly S BFS-U3-31S4M-BD (xxx)

julia> @time reset!(cam, wait_reinit = true)
  3.813247 seconds (219 allocations: 12.359 KiB)
FLIR Blackfly S BFS-U3-31S4M-BD (xxx)

julia> @time reset!(cam, wait_reinit = true)
  3.722899 seconds (219 allocations: 12.359 KiB)
FLIR Blackfly S BFS-U3-31S4M-BD (xxx)

julia> 

[IanButterworth]

@Octogonapus would you mind reviewing this. I can't formally request a review as you're not a collaborator here

[IanButterworth]

julia> using Spinnaker

julia> camlist = CameraList()
CameraList with 1 enumerated devices:
ID  Serial No.  Description
0   xxx         FLIR Blackfly S BFS-U3-31S4M-BD

julia> cam = camlist[0]
FLIR Blackfly S BFS-U3-31S4M-BD (xxx)

julia> @time reset!(cam, wait = true)
  3.818389 seconds (2.36 k allocations: 135.983 KiB, 0.20% compilation time)
FLIR Blackfly S BFS-U3-31S4M-BD (xxx)