Incorrect schema for JVM verb with map parameter

[tomdaffurn]

When a Kotlin or Java verb has a map in its signature, the schema created from it is incorrect.

This verb:

    @Export
    @Verb
    public @NotNull Map<K, V> theVerb(@NotNull Map<K, V> val) {
        return val;
    }

Generates this schema:

  export verb theVerb({K: K}) {K: K}

When it should be:

  export verb theVerb({K: V}) {K: V}