Feature 10950 Replace pycrypto with pycryptodome

Remove the pycrypto library and change encrypt and decrypt methods to work with pycryptodome.
Move encryption methods from N2VC to common.

Change-Id: I12a5f6138664ab6ebb7100c82523e91750f05f14
Signed-off-by: Gulsum Atici <gulsum.atici@canonical.com>
diff --git a/osm_common/dbmongo.py b/osm_common/dbmongo.py
index f64949d..f5c4d30 100644
--- a/osm_common/dbmongo.py
+++ b/osm_common/dbmongo.py
@@ -65,7 +65,7 @@
     conn_timout = 10
 
     def __init__(self, logger_name="db", lock=False):
-        super().__init__(logger_name, lock)
+        super().__init__(logger_name=logger_name, lock=lock)
         self.client = None
         self.db = None
         self.database_key = None