Make attributes columns too in the tables listing the verdicts

Hide attribute columns in the verdict tables

Bonus: Make VerdictTable superclass for {Unknowns,Unsafes,Safes}Table.

In the tables listing safes/unsafes/unknowns, some columns are 'output'/result (i.e. verifier time), and they are proper columns. The others are 'input' (i.e. program fragmentation), and they are called attributes in the code and cannot be removed from the view.

Allow selecting and hiding these columns, too. Such columns are always the same over a decision, and we cannot merge tables over several decisions, so hide them by default, and display them above the table instead.

'Program fragment' and 'Requirements specification' remains selected by default, as they can differ across a decision.

Displayed above if present: Klever version, Program fragmentation:{Tactic,Set}, Project:{Architecture,Configuration,Name,Version}.