tests(capd3): add tests
fix(util/scoped_vec): add missing "std::"
feat(opensmt,dsolvers): use unordered_map if possible
fix(util/hexfloat): fix style
refactor(dsolver/ode_solver): clean up
feat(CMakeLists.txt): add 'util' and 'tests' in style check
refactor(dsolvers/ode_solver): clean up step control