Menu and UI update part 1

After some struggling, I finally got around to the last big visual thing I'd postponed for so long : making the menus a bit handier and prettier. 

-Changed the text font

-New menu UI design, including new button and icon designs

-You can now navigate menus with arrow keys and confirm with pickup key (space by default). This is functional in main menu, pause menu and endlevel menus, but a few other menus aren't implemented yet

-When completing a level, you now go back to the worldmap and an unlock level animation is played, if relevant

-Fixed timed ticking while the level is paused

-Level design tweaks

As stated above some menus like the shop ui or the help menu aren't finished right now, I also deactivated the exit game button. The font might also take some time to load when you open the game, this is the kind of thing that will be fixed by adding a starting screen or something like that. Aside from these, any feedback on bugs is extremely welcome!

I still have some work ahead of me for the menus I want to have, so I'll keep working on these aspects of the project.