Docstring and variable descriptions update

[chris-ashe]

Having recently gone through part of the code I have noticed some Erros in some of the comments/docstrings

• Definition of iculbl in physics.f90 is incorrect and formatted wrong
• Definition of fhldiv in constraint_equations.f90 is wrong.
• "Limit" is spelt incorrectly in constraint equation 60
• No variable description in constraint equation 75 docstring
• No variable info in docstring for constraint equation 86 and 87
• Constraint equation 90 missing blanket switch description
• Label for fnesep in input.f90 is incorrect
• iradloss in input.f90 can have its label expanded
• i_cs_stress and alstroh are in wrong part of input.f90
• Conflicting definitions of eff_tf_cryo
• poisson_steel needs a reference
• No descritpion for quench_model
• inlet_temp_liq + outlet_temp_liq` need a units label
• DCLL module docstrings are above not below
• Declare in comments that iblanket = 2,4 is removed along with associated variables
• blktmodel is mentioned in vfblkt definition
• Comment on line 459 of divertor.py
• Documentation should say that ipfres includes the CS coil