[Team 5] Turret Selection, Game End, Further improvements to Economy

Here is a summary added in the pull request:

• Added a turret select screen, where you can choose a limited amount of turrets from a list of turrets to play with ([Team 5] Turret Picking Menu and Game Start "Lore" Screen #112)
• Polished currency, added sound on click, added a second currency for bosses. ([Team 5] - Refining Economy #121)
• Game end screen ([Team 5] UI Implementation and Design of WInning/Losing Scenarios #94)

Tests

We conducted test plans for our screens these are here:

• Story Screen Test
• Turret Selection Screen Test
• Losing Screen Test
• Level Select Screen Test