docs(openapi): document security schemes (#676)

Co-authored-by: Arun Raj M <jarnura47@gmail.com>

crates/api_models/src/enums.rs

@@ -707,6 +707,7 @@ pub enum BankNames {
     strum::Display,
     strum::EnumString,
     frunk::LabelledGeneric,
+    ToSchema,
 )]
 pub enum CardNetwork {
     Visa,

crates/api_models/src/payments.rs

@@ -382,6 +382,7 @@ pub struct Card {
     #[schema(value_type = String, example = "242")]
     pub card_cvc: Secret<String>,
     pub card_issuer: Option<String>,
+    #[schema(value_type = Option<CardNetwork>, example = "Visa")]
     pub card_network: Option<api_enums::CardNetwork>,
 }