Allow unordered OIDs (global and per-os) (#13923)

* Allow unordered OIDs (global and per-os)
Fix global no_bulk setting, was ignored before
(to fix global needed to rework Config::getCombined() a bit to allow a global prefix to be specified)
Removed invalid use of getCombined and updated tests

* fix whitespace

* update os schema

misc/config_definitions.json

@@ -5182,7 +5182,14 @@
             "section": "snmp",
             "order": 20,
             "type": "array",
-            "default": null
+            "default": []
+        },
+        "snmp.oids.unordered": {
+            "group": "poller",
+            "section": "snmp",
+            "order": 21,
+            "type": "array",
+            "default": []
         },
         "snmp.timeout": {
             "group": "poller",

misc/os_schema.json

@@ -368,6 +368,9 @@
             "properties": {
                 "no_bulk": {
                     "type": "array"
+                },
+                "unordered": {
+                    "type": "array"
                 }
             },
             "additionalProperties": false