Problem/Motivation
Static methods for creating and loading entities go against the concept of dependency injection. Furthermore, they created the need for being able to resolve an entity type from a class name, something which leads to issues when trying to introduce custom entity classes based on given scenarios. (E.g. one class to serve multiple bundles)
Proposed resolution
Mark ::create(), ::load() and ::loadMultiple() as deprecated and remove their usage from core.
Remaining tasks
EntityRepository::getEntityTypeFromClass is only being used by these static methods and the EntityNormalizer. If we can change that last class to also be smarter about how it finds the entity type ID to use, then we can get rid of getEntityTypeFromClass() altogether. If this discussion takes up too much space we can create a related issue for it.
User interface changes
None
API changes
None, you can already use the entity storage for the same functionality.
Data model changes
None
Release notes snippet
TBD
Bonus benefit: This would instantly fix #3252421: EntityInterface::loadMultiple and EntityInterface::load, if invoked on a bundle class, should only return entities of that bundle
