First step of making backend using the new service container.
Make event subscriber non static and initialize it from backend booting.
Change breadcrumb constructor to receive the service container.
Move event handlers of table tl_metamodel into new subscriber class.
Move event handlers of table tl_metamodel_attribute into new subscriber class.
Move event handlers of table tl_metamodel_dca into new subscriber class.
Move event handlers of table tl_metamodel_attribute into new subscriber class.
Move event handlers of table tl_metamodel_dcasetting into new subscriber class.

In addition, the breadcrumb handler has been renamed as it was named
wrong before.
Move event handlers of table tl_metamodel_dcasetting_condition into new subscriber class.
Change event handler of table tl_metamodel_filter breadcrumb.
Move event handlers of table tl_metamodel_filtersetting into new subscriber class.
Move event handlers of table tl_metamodel_rendersetting into new subscriber class.
Move event handlers of table tl_metamodel_rendersettings into new subscriber class.
Mark some more factories with FIXME and deprecated.
Cleanup uses in main subscriber.
Fix database usage in breadcrumbs.