lib/modules: improve mismatching class error mesage

            if m._class == null || m._class == class

            then m

            else

              throw "The module ${m._file or m.key} was imported into ${class} instead of ${m._class}."

              throw ''

                The module `${m._file or m.key}` (class: ${lib.strings.escapeNixString m._class}) cannot be imported into a module evaluation that expects class ${lib.strings.escapeNixString class}.

                Help:

                - Ensure that you are importing the correct module.

                - Verify that the module's `_class`, ${lib.strings.escapeNixString m._class} matches the expected `class` ${lib.strings.escapeNixString class}.

                - If you are using a custom class, make sure it is correctly defined and used consistently across your modules.

              ''

        else

          m: m;