Add tempest tests for share snapshot metadata

Adds positive and negative tests for share snapshot metadata api.
Works for microversion 2.73 and later.

Partially-implements: bp/metadata-for-share-resources
Depends-On: I91151792d033a4297557cd5f330053d78895eb78
Change-Id: I78cccc6bcd1b8d938b00467d07f3fd6edf7bfc6f
diff --git a/manila_tempest_tests/config.py b/manila_tempest_tests/config.py
index b62c409..2c1b375 100644
--- a/manila_tempest_tests/config.py
+++ b/manila_tempest_tests/config.py
@@ -40,7 +40,7 @@
                     "This value is only used to validate the versions "
                     "response from Manila."),
     cfg.StrOpt("max_api_microversion",
-               default="2.71",
+               default="2.73",
                help="The maximum api microversion is configured to be the "
                     "value of the latest microversion supported by Manila."),
     cfg.StrOpt("region",