Remove disconnected devices. Reorganize areas. Remove groups.

This can only be merged after this merge request has been accepted.

Remove all devices that were completely disconnected from any record. Reorganize areas based on functionality, not on physical area anymore. Remove groups because it didn't look like we needed sub-categories.

New categorization is:

  -thermal control:
    -ami1700
    -hotairblower
    -huginn
    -lakeshore224
  -pumps and valves
    -azuraP61L
    -ne1x00
    -knauervalveunifier
  -electric:
    -bursterprecision1427
  -power supply:
    -power_supplies_SY4527
    -lakeshore155
    -caenNdt1470
    -tdklambdagenesys
    -eaton-ups
  -servers and network:
    -MOXA-E1241
    -isegCc24
    -isegCc24_DREAM
  -cards and crates:
    -syn1588
    -mrfioc2
  -detectors:
    -areadetector-ess