Feature/support struct type element for other struct

[wf001]

What’s this PR?

support defining and using the struct type that have other struct type

(defschema Country {
                    :name :: string
                  })

(defschema Person {
                   :name :: string
                   :country :: Country})

(def main :: int
  (fn []
    (let [c :: Country {:name "deutsch"}
          person :: Person {:name "mike" :country c}]
      (prn (get (get person :country) :name))
      )))

What’s changed?

• List key updates or fixes here.

Anything else?

Optional: anything reviewers should pay attention to.