20 modularize the code to split up large classes (#21)

* MODULARIZE ClipService by introducing CompressionService, MetadataService, and ThumbnailService

* ADD deleteClip functionality to ClipController

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

@@ -0,0 +1,29 @@
+package com.ddf.vodsystem.services.media;
+
+import com.ddf.vodsystem.dto.CommandOutput;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.List;
+
+@Service
+public class ThumbnailService {
+    private static final Logger logger = LoggerFactory.getLogger(ThumbnailService.class);
+
+    public CommandOutput createThumbnail(File inputFile, File outputFile, Float timeInVideo) throws IOException, InterruptedException {
+        logger.info("Creating thumbnail at {} seconds", timeInVideo);
+
+        List<String> command = List.of(
+                "ffmpeg",
+                "-ss", timeInVideo.toString(),
+                "-i", inputFile.getAbsolutePath(),
+                "-frames:v", "1",
+                outputFile.getAbsolutePath()
+        );
+
+        return CommandRunner.run(command);
+    }
+}