lnms snmp:fetch command and new SNMP code (#13303)

* SNMP WIP

* cleanup, more types

* Include my snmp:fetch command

* Fix Facade name conflict

* Command WIP
remove mib

* Ignore exit code
cleanups

* Doc blocks and style fixes

* forgot to use parseOid

* Hopefully final fixes

* missed on (:

* small changes
deviates from existing code, hopefully doesn't re-add too many corner cases.

* add some simple tests, will make it easier to add more in the future when we find corner cases.

* test numeric

* API refinements, try to avoid setting textual net-snmp options directly

* change numeric to a toggle makes for nicer usage

* make ci happy

* Some errors happen only in stderr, pass that to SnmpResponse for parsing.
Add error message access

* More consistent naming

resources/lang/en/commands.php

@@ -102,6 +102,22 @@ return [
             'compat' => '[deprecated] Mimic the behaviour of gen_smokeping.php',
         ],
     ],
+    'snmp:fetch' => [
+        'description' => 'Run snmp query against a device',
+        'arguments' => [
+            'device spec' => 'Device to query: device_id or hostname/ip',
+            'oid' => 'SNMP OID to fetch.  Should be either MIB::oid or a numeric oid',
+        ],
+        'failed' => 'SNMP command failed!',
+        'oid' => 'OID',
+        'options' => [
+            'type' => 'The type of snmp query to perform :types',
+            'output' => 'Specify the output format :formats',
+            'numeric' => 'Numeric OIDs',
+        ],
+        'not_found' => 'Device not found',
+        'value' => 'Value',
+    ],
     'translation:generate' => [
         'description' => 'Generate updated json language files for use in the web frontend',
     ],