Backend MP4 conversion (#23)

* ADD conversion queue

* ADD RemuxService for MP4 conversion

* REMOVE unused conversion queue

* REORGANISE Job-related classes

* ADD Job stages

* REVERT to old commit, using Spring Async instead

* ADD asynchronous processing for video tasks

* PATCH and streamline progress tracking

* ADD asynchronous video processing and job restructuring

* REFACTOR job service method

* ADD job remux functionality

* ADD remuxing endpoint

* PATCH complete flag not updating in API response

* ADD progress type in frontend

* ADD reset functionality for job status

* PATCH missing progress bar for subsequent exports

* REDESIGN settings box

* ADD tracking video file conversion in frontend

* PATCH extension bug

* REMOVE autowired decorator

src/main/java/com/ddf/vodsystem/services/media/ThumbnailService.java

@@ -1,8 +1,8 @@
 package com.ddf.vodsystem.services.media;
 
-import com.ddf.vodsystem.dto.CommandOutput;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.scheduling.annotation.Async;
 import org.springframework.stereotype.Service;
 
 import java.io.File;
@@ -13,7 +13,8 @@ import java.util.List;
 public class ThumbnailService {
     private static final Logger logger = LoggerFactory.getLogger(ThumbnailService.class);
 
-    public CommandOutput createThumbnail(File inputFile, File outputFile, Float timeInVideo) throws IOException, InterruptedException {
+    @Async("ffmpegTaskExecutor")
+    public void createThumbnail(File inputFile, File outputFile, Float timeInVideo) throws IOException, InterruptedException {
         logger.info("Creating thumbnail at {} seconds", timeInVideo);
 
         List<String> command = List.of(
@@ -24,6 +25,6 @@ public class ThumbnailService {
                 outputFile.getAbsolutePath()
         );
 
-        return CommandRunner.run(command);
+        CommandRunner.run(command);
     }
 }