feat(router): Custom payment link config for payment create (#2741)

Co-authored-by: Kashif <46213975+kashif-m@users.noreply.github.com>
Co-authored-by: Kashif <kashif@protonmail.com>
Co-authored-by: Sahkal Poddar <sahkal.poddar@juspay.in>

crates/api_models/src/admin.rs

@@ -455,6 +455,11 @@ pub struct PrimaryBusinessDetails {
 #[derive(Clone, Debug, Deserialize, ToSchema, Serialize, PartialEq)]
 #[serde(deny_unknown_fields)]
 pub struct PaymentLinkConfig {
+    #[schema(
+        max_length = 255,
+        max_length = 255,
+        example = "https://i.imgur.com/RfxPFQo.png"
+    )]
     pub merchant_logo: Option<String>,
     pub color_scheme: Option<PaymentLinkColorSchema>,
 }