Require deriving explicitly ActionBuilder or ScorerBuilder

[cBournhonesque]

I think it would be helpful to require users to derive explicitly ActionBuilder and ScorerBuilder (and to change all the impl ActionBuilder into ActionBuilder, so that users need to provide explicitly a ActionBuilder).

1. Too much flexibility is kind of confusing, and not that helpful. When i first read the docs I was confused as to what a ScorerBuilder was, and how it was related to me just creating a struct with Component and Clone.
   I think it would be much clearer for users to have their scorers-builders/action-builders with explicit #[derive(ScorerBuilder)]

This is the exact same argument as: bevyengine/bevy#1843
In theory, it's more flexible to accept any std::fmt::Debug + Sync + Send as a ScorerBuilder (by allowing pre-existing types to be ScorerBuilders, but in practice it just makes it less clear, and i believe 99% of users won't use a pre-existing type as a scorer builder)

2. Easy labels. I think right now a user needs to explicitly implement ScorerBuilder to have a Label.
   By forcing all ScorerBuilders to have the explicit type, users could easily add the label via

 `#[derive(ScorerBuilder, label="MyScorer")]`
 pub struct MyScorer;

[zkat]

This sounds good to me.

[zkat]

This is done.