server: make attributes names, group names and emails case insensitive

In addition, group names and emails keep their casing

server/src/domain/model/groups.rs

@@ -3,14 +3,15 @@
 use sea_orm::entity::prelude::*;
 use serde::{Deserialize, Serialize};
 
-use crate::domain::types::{GroupId, Uuid};
+use crate::domain::types::{GroupId, GroupName, Uuid};
 
 #[derive(Clone, Debug, PartialEq, DeriveEntityModel, Eq, Serialize, Deserialize)]
 #[sea_orm(table_name = "groups")]
 pub struct Model {
     #[sea_orm(primary_key, auto_increment = false)]
     pub group_id: GroupId,
-    pub display_name: String,
+    pub display_name: GroupName,
+    pub lowercase_display_name: String,
     pub creation_date: chrono::NaiveDateTime,
     pub uuid: Uuid,
 }