Tests: more fixtures.

Common methods from applications/proto.py converted to the fixtures.
sysctl check moved to the specific file where it is using.
Some options moved to the constructor to have early access.

test/unit/option.py

@@ -1,7 +1,13 @@
+import os
+import platform
+
 class Options:
     _options = {
+        'architecture': platform.architecture()[0],
+        'is_privileged': os.geteuid() == 0,
         'skip_alerts': [],
         'skip_sanitizer': False,
+        'system': platform.system()
     }
 
     def __setattr__(self, name, value):