Queen Fly

[ngregrichardson]

Closes #47

Wasn't fully sure about edge cases, like when the item is picked up should it turn all blue flies and fly enemies into their respective counterparts. Also wasn't sure if heart orbital flies were also random.

[ryondinkus]

I think I wanted to change the effect to something like this:

• Blue Flies turn into random Heart Attack Flies (this is unchanged and good)
• Killing basic fly enemies will spawn a random Heart Attack Fly in their place (right now it auto-converts only black flies into Heart Orbital Flies) Here is a list of basic fly enemies: https://bindingofisaacrebirth.fandom.com/wiki/Fly

Also, don't worry about existing Blue Flies changing into Heart Attack Flies on pickup. Although, there is a weird issue where Blue Flies spawned by Rotten Heart Orbital Flies don't convert.