Previously, an entry’s potentially aliased name would be used when
checking that it has a particular name. The alias would always be
applied, irrespective of the name in the header. As a result, when
there was a clashing hash and an entry with a particular index did
not have the expected name, this would be concealed by the alias
being applied and the name check being done with the alias.

This commit reworks JarEntry to store the name in its header in
addition to its alias, if any. When checking that the entry has the
expected name, the unaliased name is passed in and the entry compares
it with the name from the header rather than the alias.

Closes gh-15981