ldb: release 2.8.0 for use in Samba 4.19.x

ldb: release 2.8.0 for use in Samba 4.19.x

* CVE-2023-0614 Not-secret but access controlled LDAP attributes can be discovered (bug 15270)
* pyldb: Raise an exception if ldb_dn_get_parent() fails
* Implement ldap_whoami in pyldb and add the RFC4532 LDB_EXTENDED_WHOAMI_OID definition
* Documentation and spelling fixes
* Add ldb_val -> bool,uint64,int64 parsing functions
* Split out ldb_val_as_dn() helper function
* add LDB_CHANGETYPE_MODRDN support to ldb_ldif_to_pyobject()
* add LDB_CHANGETYPE_DELETE support to ldb_ldif_to_pyobject()
* let ldb_ldif_parse_modrdn() handle names without 'rdn_name=' prefix
* Don't create error string if there is no error
* Avoid allocation and memcpy() for every wildcard match candidate
* Make ldb_msg_remove_attr O(n)
* pyldb: Throw error on invalid controls
* pyldb: remove py2 ifdefs
* Call tevent_set_max_debug_level(TEVENT_DEBUG_TRACE)

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15270

Signed-off-by: Jule Anger <janger@samba.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>