feat(connector): add loading screen

connector/composeApp/src/desktopMain/kotlin/tab/LoadingScreen.kt

@@ -0,0 +1,42 @@
+package tab
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import cafe.adriel.voyager.core.screen.Screen
+
+/**
+ * Loading screen for use when using a ScreenModel in a loading state.
+ * Includes a CircularProgressIndicator with text below: "Loading *loadingTitle*"
+ *
+ * @param loadingTitle `String` of the page that is being loaded.
+ */
+class LoadingScreen (private val loadingTitle: String) : Screen {
+
+    @Composable
+    override fun Content() {
+        Column (
+            modifier = Modifier
+                .fillMaxWidth()
+                .fillMaxHeight(),
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.Center,
+        ) {
+            CircularProgressIndicator(
+                modifier = Modifier.width(64.dp),
+                color = MaterialTheme.colorScheme.onSurface,
+                trackColor = MaterialTheme.colorScheme.surfaceVariant
+            )
+
+            Spacer(Modifier.size(64.dp))
+
+            Text("Loading $loadingTitle", style = MaterialTheme.typography.displaySmall )
+        }
+    }
+
+}