fix(dsolvers/ode_solver): skip ODE computation for trivial problem

skip ODE computation for trivial problems
fix(dsolvers/heuristics): fix ident, includes
tests(nra_ode/aimhigh_1_0.smt2.expected): fix the expected result (UNSAT)
fix(opensmt/egraph/Enode): change type of precision to double
fix(opensmt/api/OpenSMTContext): add constraints after processing addIntvCtr

close #45
refactor(dsolvers): clean up code
refactor(dsolvers/icp_solver): simplify rp_variable creation

 - enlarge box size at once
 - assign domain in place
 - set precision only for real vars
fix(dsolvers/icp_solver): use delta instead of 2 * delta when compute residual