feat(nodeinfo): extract and save NodeInfo information from instances to display it on instances list

We also try to detect the application actor if it's not given by NodeInfo metadata (FEP-2677)
(guessing for Mobilizon, PeerTube & Mastodon).

Closes #1392

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

test/fixtures/nodeinfo/wp-data.json

@@ -0,0 +1,24 @@
+{
+    "version": "2.0",
+    "software": {
+        "name": "wordpress",
+        "version": "6.4.2"
+    },
+    "usage": {
+        "users": {
+            "total": 1,
+            "activeMonth": 1,
+            "activeHalfyear": 1
+        },
+        "localPosts": 3,
+        "localComments": 3
+    },
+    "openRegistrations": false,
+    "protocols": [
+        "activitypub"
+    ],
+    "services": {
+        "inbound": [],
+        "outbound": []
+    }
+}