Update zero metadata API and tests

Signed-off-by: Slawomir Jankowski <slawomir.jankowski@intel.com>

test/functional/api/cas/cli.py

@@ -115,9 +115,11 @@ def print_statistics_cmd(cache_id: str, core_id: str = None, per_io_class: bool
     return casadm_bin + command
 
 
-def zero_metadata_cmd(cache_dev: str, shortcut: bool):
+def zero_metadata_cmd(cache_dev: str, force: bool = False, shortcut: bool = False):
     command = " --zero-metadata"
     command += (" -d " if shortcut else " --device ") + cache_dev
+    if force:
+        command += (" -f" if shortcut else " --force")
     return casadm_bin + command