fix: remove old navigation controller delegate

app/src/main/java/com/cappielloantonio/tempo/navigation/NavigationDelegate.java

@@ -1,48 +0,0 @@
-package com.cappielloantonio.tempo.navigation;
-
-import android.view.View;
-
-import androidx.media3.common.util.UnstableApi;
-
-import com.cappielloantonio.tempo.databinding.ActivityMainBinding;
-import com.cappielloantonio.tempo.ui.activity.MainActivity;
-
-/*
- The goal of this class is to stop instanciating MainActivity on each fragment */
-@UnstableApi
-public final class NavigationDelegate {
-
-    private static final NavigationDelegate INSTANCE = new NavigationDelegate();
-
-    private MainActivity activity;
-    private boolean visible = true;
-
-    private NavigationDelegate() {}
-
-    public static NavigationDelegate getInstance() {
-        return INSTANCE;
-    }
-
-    /* Call inside onCreate() in MainActivity giving as argument `this` */
-    public void bind(MainActivity activity) {
-        this.activity = activity;
-    }
-
-    /* Call inside onDestroy() in MainActivity*/
-    public void unbind() {
-        this.activity = null;
-    }
-
-    public static boolean isVisible() {
-        return INSTANCE.visible;
-    }
-
-    /** Change visibility and update the UI on the UI thread. */
-    public void setVisibility(final boolean visible) {
-        this.visible = visible;
-        ActivityMainBinding bind = activity.getBinding();
-        bind.bottomNavigation.setVisibility(visible
-                            ? View.VISIBLE
-                            : View.GONE);
-    }
-}