Resolve "Fix safety overrides on Sample Environment Meerstetter LTR1200"

Closes #3956 (closed)

New derived class Ltr1200SampleEnv for meerstetter temperature controller that does not break safety interlocks on sample environment pool equipment.

Change the behavior of start regulation for 'hw_enable' instead of forcing it ON (and overriding safety signal).

When installing this controller belonging to the sample env pool, use the class Ltr1200SampleEnv in the yamlfile.

Keep the Ltr1200 class to beamline who never implemented the safety interlock on their controller (ID06?).

Beamline that requires a change in their yaml : ID31 ID10 (they borrowed our controller in the past). Failure to do so will kill our equipment.