ldb: activating <= and >= indexing for integers

ldb: activating <= and >= indexing for integers

Activating <= and >= mdb indexing in samba for int32 and int64 attributes by:
1. Adding index_format_fn to LDB_SYNTAX_SAMBA_INT32 in ldb_samba
2. Cloning the 64bit LDB_SYNTAX_INTEGER type as LDB_SYNTAX_ORDERED_INTEGER
3. Adding index_format_fn to the new type
4. Modifying LargeInteger use the new type in samba schema
5. Bumping the index version to trigger reindexing

Pair-programmed-with: Garming Sam <garming@catalyst.net.nz>

Signed-off-by: Aaron Haslett <aaronhaslett@catalyst.net.nz>
Signed-off-by: Garming Sam <garming@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>