BLOG-94 refactor: change image ID from Option<i32> to i32 in Image struct and related mappers

backend/feature/image/src/adapter/delivery/image_request_dto.rs

@@ -8,7 +8,7 @@ pub struct ImageRequestDto {
 impl ImageRequestDto {
     pub fn into_entity(self) -> Image {
         Image {
-            id: None,
+            id: -1,
             mime_type: self.mime_type,
             data: self.data,
         }

backend/feature/image/src/adapter/gateway/image_db_mapper.rs

@@ -1,7 +1,7 @@
 use crate::domain::entity::image::Image;
 
 pub struct ImageDbMapper {
-    pub id: Option<i32>,
+    pub id: i32,
     pub mime_type: String,
 }
 

backend/feature/image/src/domain/entity/image.rs

@@ -1,5 +1,5 @@
 pub struct Image {
-    pub id: Option<i32>,
+    pub id: i32,
     pub mime_type: String,
     pub data: Vec<u8>,
 }

backend/feature/image/src/framework/db/image_db_service_impl.rs

@@ -54,7 +54,7 @@ impl ImageDbService for ImageDbServiceImpl {
         match image_record {
             Ok(record) => match record {
                 Some(record) => Ok(ImageDbMapper {
-                    id: Some(record.id),
+                    id: record.id,
                     mime_type: record.mime_type,
                 }),
                 None => Err(ImageError::NotFound),