simplify hyperion restart

[rtuck99]

Fixes

• simplify hyperion_restart() for blueapi #1737
• Restarting GDA server appears to kill off hyperion-blueapi #1739

Also requires

• https://gerrit.diamond.ac.uk/c/gda/gda-mx/+/44987

Link to dodal PR (if required): #N/A

As used from GDA, hyperion_restart() should always kill all hyperion processes, however separate launching of supervisor and blueapi is retained for use direct from the command line via run_hyperion.sh.
Blueapi is now started in a separate process group to avoid being sent the SIGINT by gda_launcher which was terminating the process on GDA server shutdown.

Checks for reviewer

• Would the PR title make sense to a user on a set of release notes

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.87%. Comparing base (3f57116) to head (a6b8dff).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1744   +/-   ##
=======================================
  Coverage   92.87%   92.87%           
=======================================
  Files         156      156           
  Lines        8563     8563           
=======================================
  Hits         7953     7953           
  Misses        610      610           

Components	Coverage Δ
i24 SSX	77.15% <ø> (ø)
hyperion	98.73% <ø> (ø)
other	98.31% <ø> (ø)

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