Deconstruct `AccountComponentCode`'s library into components

[igamigo]

#2142 introduces the concept of AccountComponentCode, which currently just wraps a Library. We could deconstruct its library into its components, providing getters where necessary:

Probably not for this PR, but I think we should deconstruct Library into relevant components here - similar to how ?we do this for NoteScript and TransactionScript. It could look something like:

pub struct AccountComponentCode {
    mast: Arc<MastForest>,
    exports: Vec<ProcedureExport>,
}

Originally posted by @bobbinth in #2142 (comment)