Refactor: Update package structure and implement bottom navigation

This commit refactors the package structure for Gradle convention plugins and introduces bottom navigation to the application.

Key changes:
- Moved Gradle convention plugin files from `dev.adriankuta.partymania` to `dev.adriankuta.flights`.
- Added `TopLevelDestination.kt` to define top-level navigation destinations with icons, titles, and routes.
- Implemented `FlightsBottomBar` Composable in `FlightsApp.kt` to display a `NavigationBar` with items for each `TopLevelDestination`.
- Updated `FlightsNavGraph.kt`:
    - Renamed from `FlightsNavGraph.kt` to `navigation/FlightsNavGraph.kt`.
    - Added `navigateToTopLevelDestination` extension function for `NavController` to handle navigation to top-level destinations with appropriate `NavOptions`.
- Updated `HomeNavigation.kt`:
    - Added `navigateToHome` extension function for `NavController`.
- Added `strings.xml` for `ui:home` module with `home_screen_title`.
- Ensured Kotlin serialization plugin is correctly applied in `app/build.gradle.kts`.

ui/home/src/main/kotlin/dev/adriankuta/flights/ui/home/navigation/HomeNavigation.kt

@@ -2,7 +2,9 @@
 
 package dev.adriankuta.flights.ui.home.navigation
 
+import androidx.navigation.NavController
 import androidx.navigation.NavGraphBuilder
+import androidx.navigation.NavOptions
 import androidx.navigation.compose.composable
 import dev.adriankuta.flights.ui.home.HomeScreen
 import kotlinx.serialization.Serializable
@@ -10,6 +12,12 @@ import kotlinx.serialization.Serializable
 @Serializable
 data object HomeRoute
 
+fun NavController.navigateToHome(
+    navOptions: NavOptions,
+) {
+    navigate(route = HomeRoute, navOptions = navOptions)
+}
+
 fun NavGraphBuilder.homeScreen() {
     composable<HomeRoute> {
         HomeScreen()

ui/home/src/main/res/values/strings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="home_screen_title">Search Flight</string>
+</resources>