More precise and correct behaviour in pragmas verification; Added better management of Expression Solvers with states

Added cli single pragma query for model-checker. Changed cli avatar-rg layout and flags. Solved a bug in the interpreter. Solved a possible null pointer exp in AvatarExpressionAttribute. Added test for single pragma query. Added rg generation during property study.

This reverts merge request !325

Expression solver can represent states of the model as variables. Now expression solver proves also safaty pragmas on states.

New guard evaluator, using precomputing and the optimized expression solver ~80x speedup in modelchecker

Added a new boolean expression evaluator with a binary tree structure to reduce the high number of String operations. Used for now only on safety