feat: output verification using custom tags

[vincentpalma]

To consider: maybe what we call output in the tags should be renamed output_hash and we could add another tag output of type Vec<Vec> that encodes the output directly (would be [0x1] in the test example) and users could choose one or another depending on use cases.

[YofiY]

an error should be thrown

[vincentpalma]

I think its better not to throw. It will anyways never happen but its not the responsibility of this function to check this for every tag.

[YofiY]

It would be cleaner to use a create a HashMap<TagKind, Tag> as done for the analoguous fn for P2PK in nut11

        let tags: HashMap<TagKind, Tag> = tags
            .into_iter()
            .map(|t| Tag::try_from(t).unwrap())
            .map(|t| (t.kind(), t))
            .collect();

and then match on each supported tag kind:
i.e. for output_hash

let output_hash = match tags.get(&TagKind::Custom(...))...

[vincentpalma]

The problem is that Tag is defined for the conditions of nut11, which we don't care about, and adding a new Tag to nut11 is not the right thing to do if we can avoid it imo.

[YofiY]

lgtm