logs: replace every fmt::print with a lg call instead (#1368)

Favors the `lg` namespace over `fmt` directly, as this will output the
logs to a file / has log levels.

I also made assertion errors go to a file, this unfortunately means
importing `lg` and hence `fmt` which was attempted to be avoided before.
But I'm not sure how else to do this aspect without re-inventing the
file logging.

We have a lot of commented out prints as well that we should probably
cleanup at some point / switch them to trace level and default to `info`
level.

I noticed the pattern of disabling debug logs behind some boolean,
something to consider cleaning up in the future -- if our logs were more
structured (knowing where they are coming from) then a lot this
boilerplate could be eliminated.

Closes #1358

decompiler/IR2/AtomicOpForm.cpp

@@ -119,14 +119,14 @@ FormElement* SetVarOp::get_as_form(FormPool& pool, const Env& env) const {
             menv->disable_use(src_var);
           }
 
-          // fmt::print("marked {} as dead set\n", to_string(env));
+          // lg::print("marked {} as dead set\n", to_string(env));
         }
       } else if (m_src.get_arg(0).is_sym_val() && m_src.get_arg(0).get_str() == "#f" &&
                  m_dst.reg().allowed_local_gpr()) {
         auto& ri = env.reg_use().op.at(m_my_idx);
         if (ri.written_and_unused.find(dst().reg()) != ri.written_and_unused.end()) {
           result->mark_as_dead_false();
-          // fmt::print("marked {} as dead set false\n", to_string(env));
+          // lg::print("marked {} as dead set false\n", to_string(env));
         }
       }
     }