Update v0.2.02 QoL and Balance

Update v0.2.02 QoL and Balance

Hey guys! With this update I am bringing most requested quality of life features into the game and a little bit of balancing.

I hope I didn't break anything and cause new bugs (I most certainly did).

- Reworked the Frost Mage tower, now it does AoE damage and slow and is actually good!

- You can now sell towers for gold!

- Added new targeting option: lowest health enemy

- Added level indicators for towers

- Added a precast indicator for the Lightning Strike

- Added better indication and animation for Arcane Overcharge

- Added Space bar hotkey for starting waves

- Most UI bugs previously reported by players were fixed

- A lot of balancing changes to make all towers viable in midgame