Fix mouse input events being read multiple times

[tim-blackbird]

@alice-i-cecile I saw you were busy moving at the moment (congrats c:), but this should fix the issue with Bevy 0.12.1 that people mentioned in the discord.

Fixes #285

Cleanest fix I could come up with was to replace the Events<T> in InputStreams with Vec<T>, and then collecting the events into that with an EventReader in update_action_state.

[tim-blackbird]

There's no way to correctly read the events from here.
Same thing for the from_world method on MutableInputStreams .

[alice-i-cecile]

Thanks a ton <3 Yeah, I'm moving currently but I have a bit in a cafe and I'll merge and ship this.

[keis]

I think this change broke the egui feature. I'm getting this compile error on 0.11.2

   --> /home/keis/.cargo/registry/src/index.crates.io-6f17d22bba15001f/leafwing-input-manager-0.11.2/src/systems.rs:130:9
    |
127 |       let (mouse_buttons, mouse_wheel) = if ctx.is_pointer_over_area() || ctx.wants_pointer_input() {
    |  ________________________________________-
128 | |         (None, None)
    | |         ------------ expected because of this
129 | |     } else {
130 | |         (mouse_buttons, mouse_wheel)
    | |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `(Option<_>, Option<_>)`, found `(Option<&Input<MouseButton>>, Vec<MouseWheel>)`
131 | |     };
    | |_____- `if` and `else` have incompatible types
    |
    = note: expected tuple `(std::option::Option<_>, std::option::Option<_>)`
               found tuple `(std::option::Option<&Input<MouseButton>>, std::vec::Vec<bevy::input::mouse::MouseWheel>)`

[tim-blackbird]

Sorry about that. I'll have another PR up in a bit.

[tim-blackbird]

Got a fix for that here: #421.
In the mean time, it does compile if you keep the default features (ui and block_ui_interactions) enabled.