Add tests for share server migration

This patch adds new positive and negative tests for
share server migration.

Partially-implements: bp share-server-migration
Co-Authored-By: Daniel Tapia <danielarthurt@gmail.com>

Change-Id: Ice973bd2ad15bfb432e51da595b53c0480adba14
Depends-On: Ic0751027d2c3f1ef7ab0f7836baff3070a230cfd
Depends-On: I46a0cee0a4625d950f02fa7a5bf612de926451b5
Depends-On: I813801fd64d4d605c0a4fe06c7a130ad00865b6d
diff --git a/manila_tempest_tests/common/constants.py b/manila_tempest_tests/common/constants.py
index 88fe411..2750760 100644
--- a/manila_tempest_tests/common/constants.py
+++ b/manila_tempest_tests/common/constants.py
@@ -97,6 +97,7 @@
 
 # Share servers
 SERVER_STATE_ACTIVE = 'active'
+SERVER_STATE_INACTIVE = 'inactive'
 SERVER_STATE_CREATING = 'creating'
 SERVER_STATE_DELETING = 'deleting'
 SERVER_STATE_ERROR = 'error'
@@ -104,3 +105,5 @@
 SERVER_STATE_MANAGE_STARTING = 'manage_starting'
 SERVER_STATE_UNMANAGE_ERROR = 'unmanage_error'
 SERVER_STATE_UNMANAGE_STARTING = 'unmanage_starting'
+STATUS_SERVER_MIGRATING = 'server_migrating'
+STATUS_SERVER_MIGRATING_TO = 'server_migrating_to'