feat: deprecate create_or_update in favour of upsert

The `create_or_update` method has been deprecated and replaced by
`upsert` for clarity and consistency with common database terminology.

This commit also removes the file `src/entity.rs` which has been
forgotten in earlier commits and was no longer part of Georm.

examples/postgres/users-comments-and-followers/src/models/profiles.rs

@@ -58,7 +58,7 @@ impl Profile {
         &mut self,
         display_name: Option<String>,
         bio: Option<String>,
-        executor: E
+        executor: E,
     ) -> Result<Self>
     where
         E: sqlx::Executor<'e, Database = sqlx::Postgres>,

examples/postgres/users-comments-and-followers/src/models/users.rs

@@ -69,7 +69,7 @@ impl User {
     pub async fn get_user_by_id_or_select<'e, E>(
         id: Option<i32>,
         prompt: &str,
-        executor: E
+        executor: E,
     ) -> Result<Self>
     where
         E: sqlx::Executor<'e, Database = sqlx::Postgres>,
@@ -128,8 +128,7 @@ impl User {
         Ok(user)
     }
 
-    pub async fn update_profile(id: Option<i32>, pool: &sqlx::PgPool) -> Result<(User, Profile)>
-    {
+    pub async fn update_profile(id: Option<i32>, pool: &sqlx::PgPool) -> Result<(User, Profile)> {
         let prompt = "Select the user whose profile you want to update";
         let user = Self::get_user_by_id_or_select(id, prompt, pool).await?;
         let profile = match user.get_profile(pool).await? {