Fixed next_split call in pop (#6966)

* Give users ability to see if propagation failed

* Skip propagations in the new core if they are already satisfied

* Fix registration in final

* Don't make it too complicated...

* Fixed next_split when called in pop
Made delay_units available even without quantifiers

* Missing push calls before "decide"-callback

src/smt/smt_context.cpp

@@ -4122,7 +4122,6 @@ namespace smt {
             // Moreover, I backtrack only one level.
             bool delay_forced_restart =
                 m_fparams.m_delay_units &&
-                internalized_quantifiers() &&
                 num_lits == 1 &&
                 conflict_lvl > m_search_lvl + 1 &&
                 !m.proofs_enabled() &&