docs: improve image: better color
PLANNER-173 excluding static and final fields, adding fields of super to the fieldsCache to support proxied classes (such as jpa entities or cdi beans)
adding cloning support for solutions with private no-arg constructors
cloner: recursing to superclass is already done in copyFields() + ignore all static fields (not just final fields)
code style
merge Immutable and Private Solution into TestdataAccessModifierSolution and add more challenges
we don't use suppresswarnings on rest of code either yet - use it everywhere or nowhere