SketchSolver Refactoring: Eliminate SolveSpace as a sketch solver.
* Improve SketchSolver_Manager to add features placed in a single sketch into a single group
* Remove unnecessary IDs for entities and parameters. Do not set GroupID for such kind of elements.
* Remove unnecessary IDs for groups
* Check feature validity on at the very beginning of processing.
* Fix problems when deleting temporary constraint built for correct restart of an operation.
* Remove data structure to store lists of coincident points.
* Integrate SketchSolver sources into PlaneGCSSolver plugin
* Take out ParameterWrapper
* Move converting and removing entities to specific classes
* Remove notifications on changing point-point coincidences.
* Update processing Fixed constraint (make it more natural to PlaneGCS). Remove Movement constraint as unneeded.
* Repair Point-point coincidence and the Fixed constraints
* Fix incorrect processing of the Update event.
* Repair Point-on-Line and Point-on-Circle constraints.
* Repair processing of external features
* Processing of point-point multi-coincidence has been updated. Unit test has been improved.
* Repair constraints: Horizontal, Vertical, Parallel, Perpendicular, Radius, Distance, Length, Equal and Tangent
* Fix issue that arc cannot be created on the sketch with constraints
* Repair Angle and Middle point constraints.
* Repair Multi-Rotation and Multi-Translation constraints.
* Introduce Updaters to send changed features to interested object only.
* Remove the Fixed constraint applying on the external features.
* Update Multi-* constraints to use Updaters.
* Mirror constraint redesign
* Remove obsolete std::dynamic_pointer_cast
* Optimize blocking events while solving constraints
* Update Coincidence and Middle Point constraints processing (move checking multi coincidence to the constraint layer)
