[BUGFIX] Cleanup and simplify class alias handling

There were several issues with the implementation
of class alias handling. Most importantly the
early instance alias cache depended on TYPO3_MODE
which in turn triggered a full class cache
initialization when this cache was missing in one
context.

Additionally eval() calls needed to be used in
certain situations and the building of the cache
files introduced additional complexity.

With this change the cache for early instances
is completely removed and replaced by a simple
setAliasFoClassName() call.

Resolves: #55559
Releases: 6.2
Change-Id: I59958419f28a4ff1d6de4add94ee611b56070068
Reviewed-on: https://review.typo3.org/27236
Reviewed-by: Andreas Wolf
Tested-by: Andreas Wolf
Reviewed-by: Marcin Sągol
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring
Reviewed-by: Helmut Hummel
Tested-by: Helmut Hummel