Custom ice traps

[rrealmuto]

Adds setting to select a custom amount of ice traps. When pots/crates/etc. are enabled, there is a pretty big jump between Ice Trap "Mayhem" and "Onslaught" because all of the junk items from pots don't get included under Mayhem. This setting allows more fine-grained control over how many ice traps are in the seed.

Two additional items are available under the "Ice Traps" drop down:

• Custom (count): Specify an exact amount of "Junk" items to be converted to Ice Traps
• Custom (%): Specify a percentage of the "Junk" items to be converted to Ice Traps.

In both of these cases, "Junk" items includes base pool junk.

[cjohnson57]

Requesting to resolve merge conflicts/update to the new typing reqs, this PR is fairly small so hopefully shouldn't be too bad

[rrealmuto]

Still need to make sure this actually works but I rebased it.

[rrealmuto]

It seems to be working now. Found a problem where it wasn't properly working because of pending junk but I think that's fixed now.

[cjohnson57]

A couple things:

The count option goes up to 4 digits, but it looks like the box only displays up to 3. You'll probably have to dig into the forbidden CSS files for this

Just to confirm, I noticed that if I set the count way too high, instead of erroring it simply gives the same amount of ice traps as if I set it to 100%, this is intended behavior? (Ftr I think it's good)

[fenhl]

Got some code style nits, this seems good other than that.

[fenhl]

I must have done something wrong so GitHub didn't auto-close this PR, but this was merged in a75ab38.