Adding missing constraints to parameterisations

[kj5248]

Description of issue / requirement to address

Came around from issue #727. Sometimes the optimisation can result in odd shapes due to the lack of constraints on certain parameterisations such as the PictureFrame. Currently PrinctonD, TripleArc and SextupleArc have contraints whilst PolySpline and PictureFrame do not. Needs to be decided for each class whether a constraint is necessary and if so adding one. It would be necessary to add one if the parameterisation class is often used with unfixed variables.

Related file is bluemira/geometry/parameterisations.py

Additional work on constraints

For classes with a constraint a check of the produced shape could be performed within the create_shape function of each class to check violation of the class constraints.