[auth] Adding icon for Belo (#4548)

## Description
Belo is a popular fintech in Argentina and Brazil.

auth/assets/custom-icons/_data/custom-icons.json

@@ -72,6 +72,10 @@
         "NGA社区"
       ]
     },
+    {
+      "title": "Belo",
+      "hex": "5717d4"
+    },
     {
       "title": "Bethesda",
       "altNames": [

auth/assets/custom-icons/icons/belo.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="87" height="87" fill="none"><rect width="86.1667" height="86.2257" fill="#5717D4" rx="14.7344"/><path fill="#00FFB2" fill-rule="evenodd" d="M24.448 35.976c.461-.504 1.242-.536 1.767-.098a26.25 26.25 0 0 0 16.867 6.09 26.25 26.25 0 0 0 16.867-6.09c.525-.438 1.306-.406 1.767.098l4.178 4.562a1.204 1.204 0 0 1-.092 1.732 34.9 34.9 0 0 1-22.72 8.36 34.9 34.9 0 0 1-22.72-8.36 1.204 1.204 0 0 1-.092-1.732z" clip-rule="evenodd"/></svg>