Support 'install' command in org.osbuild.modprobe stage

Add support for new 'install' command in the org.osbuild.modprobe stage.

Extend the unit test coverage to test the new command.

Signed-off-by: Tomas Hozza <thozza@redhat.com>

test/data/stages/modprobe/b.json

@@ -481,6 +481,19 @@
             }
           ]
         }
+      },
+      {
+        "name": "org.osbuild.modprobe",
+        "options": {
+          "filename": "firewalld-sysctls.conf",
+          "commands": [
+            {
+              "command": "install",
+              "modulename": "nf_conntrack",
+              "cmdline": "/usr/sbin/modprobe --ignore-install nf_conntrack $CMDLINE_OPTS && /usr/sbin/sysctl --quiet --pattern 'net[.]netfilter[.]nf_conntrack.*' --system"
+            }
+          ]
+        }
       }
     ]
   },

test/data/stages/modprobe/b.mpp.json

@@ -56,6 +56,19 @@
             }
           ]
         }
+      },
+      {
+        "name": "org.osbuild.modprobe",
+        "options": {
+          "filename": "firewalld-sysctls.conf",
+          "commands": [
+            {
+              "command": "install",
+              "modulename": "nf_conntrack",
+              "cmdline": "/usr/sbin/modprobe --ignore-install nf_conntrack $CMDLINE_OPTS && /usr/sbin/sysctl --quiet --pattern 'net[.]netfilter[.]nf_conntrack.*' --system"
+            }
+          ]
+        }
       }
     ]
   }

test/data/stages/modprobe/diff.json

@@ -1,7 +1,8 @@
 {
   "added_files": [
     "/usr/lib/modprobe.d/disallow-modules.conf",
-    "/usr/lib/modprobe.d/disallow-additional-modules.conf"
+    "/usr/lib/modprobe.d/disallow-additional-modules.conf",
+    "/usr/lib/modprobe.d/firewalld-sysctls.conf"
   ],
   "deleted_files": [],
   "differences": {}