feat: use postcard for redis serde (#6956)

* redo error handling in xredis

* give proper types to metadata fields

* add round-trip tests

* inline loader enum metadata fields

* postcard roundtrips

* prepare

* bump redis key version

* serde-binhum

* clippy

* fix

* fix frontend checking existence of component fields rather than non-null-ness

* prepare

apps/labrinth/src/models/v3/billing.rs

@@ -4,6 +4,7 @@ use crate::models::ids::{
 use ariadne::ids::UserId;
 use chrono::{DateTime, Utc};
 use serde::{Deserialize, Serialize};
+use serde_binhum::serde_binhum;
 use std::collections::HashMap;
 
 #[derive(Serialize, Deserialize)]
@@ -14,7 +15,7 @@ pub struct Product {
     pub unitary: bool,
 }
 
-#[derive(Serialize, Deserialize)]
+#[serde_binhum]
 #[serde(tag = "type", rename_all = "kebab-case")]
 pub enum ProductMetadata {
     Midas,
@@ -55,7 +56,7 @@ pub struct ProductPrice {
     pub currency_code: String,
 }
 
-#[derive(Serialize, Deserialize)]
+#[serde_binhum]
 #[serde(tag = "type", rename_all = "kebab-case")]
 pub enum Price {
     OneTime {

apps/labrinth/src/models/v3/notifications.rs

@@ -12,6 +12,7 @@ use crate::routes::ApiError;
 use ariadne::ids::UserId;
 use chrono::{DateTime, Utc};
 use serde::{Deserialize, Serialize};
+use serde_binhum::serde_binhum;
 use uuid::Uuid;
 
 #[derive(Serialize, Deserialize)]
@@ -151,7 +152,8 @@ impl NotificationType {
     }
 }
 
-#[derive(Serialize, Deserialize, Clone)]
+#[derive(Clone)]
+#[serde_binhum]
 #[serde(tag = "type", rename_all = "snake_case")]
 pub enum NotificationBody {
     ProjectUpdate {