Separating "Enemy Randomization %" option into two

[Twichigo]

Currently, it adds extra enemies and randomizes their weapons at the same time. It would be amazing if those were separate modifiers.

Example of starting the game with the current behavior. I set it to 100, the very first enemy drops Assault Shotgun, which you normally find in Mission 4. The next enemy drops Plasma Rifle, which is found in Mission 5. With this I can't enjoy having even a bit more of enemies for extra challenge without them spoiling weapon progression and giving me advanced items right off the bat.

This will be useful for low/no rando runs. If extra enemies are added, but weapon randomization is left at 0 they should only use the same weapons with the same weighting as the vanilla enemies on that map. Say, the very first mission very-very rarely extra enemies could possess a flamethrower, representing a singular default enemy with it, few might have a Sniper Rifle, the majority uses just a pistol and a knife, etc.