add algebraic type class instances for Enum.finite* types

Quickcheck_Types is no longer needed due to 51aa30c9ee4e

clarified focus and key handling -- more like SideKick; avoid resetting input map with its potentially confusion propagation of key events to unrelated components, e.g. main text area or tree scrollbar;

merged

tuned signature according to Scala version -- prefer explicit argument;

tuned signature;

generic process wrapping in Prover; clarified module arrangement;

more abstract Prover.System_Process, which allows to bypass Isabelle_System.Managed_Process;

allow hyperlinks without offset, just in case the prover emits such reports, despite Position.is_reported;

more frugal standard message properties;

tuned;

clarified Position.Identified: do not require range from prover, default to command position;

maintain Command_Range position as in ML;

more compact representation of special string values;

separate Java FX modules -- no need to include jfxrt.jar by default;

tuned signature;

tuned signature;

separate module Command_Span: mostly syntactic representation; potentially prover-specific Output_Syntax.parse_spans;

tuned signature;

clarified Command_Span in accordance to Scala (see also c2c1e5944536);

tuned output, in accordance to transaction name in ML;

more explicit type Span in Scala, according to ML version;

clarified modules;

clarified signature: entity serial number is not position id;

avoid needless (and wrong w.r.t. sorts) generation of type variables; tuned whitespaces;

improved unfolding of 'let's

tuned whitespace

less aggressive unfolding; removed debugging;

document property 'set_cases'

generate 'set_cases' theorem for (co)datatypes