Optimise the default inverse CDF function for continuous distributions

Many distributions only compute the inverse CDF to 1e-9 relative error. Some fail to compute when the input p value maps to a very small x value (e.g. 1e-50). This is related to the defaults for the brent solver used in the default implementation.

Investigation of tolerances in the brent solver discovered a bug when evaluating very small objective functions (NUMBERS-168).

The brent solver requires a release to be used with this fix so work can use a local copy until all issues with it have been resolved, and the changes ported back to numbers.