tests: test e2fsck's handling of bad symlinks

tests: test e2fsck's handling of bad symlinks

Add a test which verifies that e2fsck will detect a variety of bad
symlinks, both fast and slow, and with several combinations of
filesystem features including extents, encryption, and inline_data.
There was already a similar test (f_badsymlinks), but it's an old test
that doesn't use any of these newer filesystem features.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>