Refactor codebase resolving warnings and remove self-package imports

lib/view/pages/timetable/timeRegionComponent.dart

@@ -0,0 +1,58 @@
+import 'package:flutter/material.dart';
+import 'package:syncfusion_flutter_calendar/calendar.dart';
+
+class TimeRegionComponent extends StatefulWidget {
+  final TimeRegionDetails details;
+  const TimeRegionComponent({Key? key, required this.details}) : super(key: key);
+
+  @override
+  State<TimeRegionComponent> createState() => _TimeRegionComponentState();
+}
+
+class _TimeRegionComponentState extends State<TimeRegionComponent> {
+  @override
+  Widget build(BuildContext context) {
+    String text = widget.details.region.text!;
+    Color? color = widget.details.region.color;
+
+    if (text == 'centerIcon') {
+      return Container(
+        color: color,
+        alignment: Alignment.center,
+        child: Icon(
+          widget.details.region.iconData,
+          size: 17,
+          color: Theme.of(context).primaryColor,
+        ),
+      );
+    } else if(text.startsWith('holiday')) {
+      return Container(
+        color: color,
+        alignment: Alignment.center,
+        child: Column(
+          children: [
+            const SizedBox(height: 5),
+            const Icon(Icons.cake),
+            const Text("FREI"),
+            const SizedBox(height: 5),
+            RotatedBox(
+              quarterTurns: 1,
+              child: Text(
+                text.split(":").last,
+                maxLines: 1,
+                style: const TextStyle(
+                  fontWeight: FontWeight.bold,
+                  fontSize: 15,
+                  decorationStyle: TextDecorationStyle.dashed,
+                  letterSpacing: 2,
+                ),
+              ),
+            ),
+          ],
+        ),
+      );
+    }
+
+    return const Placeholder();
+  }
+}