Added new UI and Levels

In this development journey, I learned that using UNITY's Legacy UI elements are not good but the new TextMeshPro UI elements are way better at everything.

Added new buttons and replaced the buttons with text to Images directly text on them, this way it looks way better and clean.

Now although the new levels are not as new as I am saying 😜 but they still contain a new Enemy Aircraft and some new loading screen animation slight blur screen animation that I added when the scene changes and the screen goes black and the new scenes loads. I refered to Brackeys video tutorial channel for this and was quit helpfull, In this process I faced an error too and got solved by taking help from a senior friend GameDev.