Generalize the naming conventions in DFR3 plotting methods - they are currently specific to fragilities

[ghost]

With the recent changes to DFR3 service and pyincore, there is no difference in the methods used to plot any kind of DFR3 curves(F/R/R). But, the methods in pyincore code use fragility specific naming conventions. We should update them to be more generic, so the same methods can be used for plotting repairs, restorations etc.

example:

def get_fragility_plot(fragility_set, title=None, dimension=2, limit_state="LS_0",
                           custom_curve_parameters={}, **kwargs):

this can be called get_curve_plot() and limit_state can be removed or generalized, because for R/R this can be percent_functional ("PF_0")