[feat&optimize] Group Batch Download, Optimize download logic

app/src/main/java/com/acitelight/aether/model/VideoDownloadItemState.kt

@@ -0,0 +1,31 @@
+package com.acitelight.aether.model
+
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import com.tonyodev.fetch2.Status
+
+class VideoDownloadItemState(
+    val id: Int,
+    fileName: String,
+    filePath: String,
+    url: String,
+    progress: Int,
+    status: Status,
+    downloadedBytes: Long,
+    totalBytes: Long,
+    klass: String,
+    vid: String,
+    val type: String
+) {
+    var fileName by mutableStateOf(fileName)
+    var filePath by mutableStateOf(filePath)
+    var url by mutableStateOf(url)
+    var progress by mutableStateOf(progress)
+    var status by mutableStateOf(status)
+    var downloadedBytes by mutableStateOf(downloadedBytes)
+    var totalBytes by mutableStateOf(totalBytes)
+
+    var klass by mutableStateOf(klass)
+    var vid by mutableStateOf(vid)
+}