new icon: dbvisualizer (original) (#2837)

* new icon: dbvisualizer (original)

Adds the DbVisualizer logo (squircle version from dbvis.com) as an
original icon and registers it in devicon.json.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LAQkgE6ZfxcmSHQRn4Q3uE

* add plain version for dbvisualizer

As requested in review: the original has multiple paths and colours, so
add a one-colour, united-path plain SVG and use it for the font icon.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LAQkgE6ZfxcmSHQRn4Q3uE

---------

Co-authored-by: rajthilak0610-ship-it <rajthilak0610-ship-it@users.noreply.github.com>
Co-authored-by: Claude Sonnet 5.5 <noreply@anthropic.com>
Co-authored-by: Yash <yashsaini18166@gmail.com>

Author: 3 people

devicon.json

@@ -3262,6 +3262,28 @@
         "color": "#382a24",
         "aliases": []
     },
+    {
+        "name": "dbvisualizer",
+        "altnames": [
+            "DbVis"
+        ],
+        "tags": [
+            "database",
+            "sql",
+            "tool"
+        ],
+        "versions": {
+            "svg": [
+                "original",
+                "plain"
+            ],
+            "font": [
+                "plain"
+            ]
+        },
+        "color": "#24c780",
+        "aliases": []
+    },
     {
         "name": "debian",
         "altnames": [],