[views] do not eat the self._cw.message in LogFormView (closes #12421177) accessing self._cw.message now(?) eat the message, so don't call "self._cw.message" twice.

[server] make InternalManager.name() return an empty string (closes #12418708) Otherwise the notification emails sent via an internal_session never honor the EMAIL.sender-name configuration option.

[test/migractions] work around drop_cube not deleting final etypes Closes #10096736

[hooks] deleting a final entity type shouldn't try dropping an sql table