Make the whole read-map be dynamic

[petterik]

Let the values of the lajt-reads be a function taking the env. Right now it's defined as maps everywhere. Example where the query changes depending on params:

(defmethod lajt-read :query/store-items
  [_]
  (fn [env]
    (merge-with merge
                {:remote true
                 :query  {:find '[[?e ...]]}}
                (if (seq (get-in env [:route-params :navigation]))
                  {:query  '{:where [[?s :store/items ?e]
                                     [?e :store.item/section ?n]
                                     [?n :store.section/path ?p]
                                     [?e :store.item/name _]]}
                   :params {'?s [:route-params :store-id]
                            '?p [:route-params :navigation]}}
                  {:query  '{:where [[?s :store/items ?e]
                                     [?e :store.item/name _]]}
                   :params {'?s [:route-params :store-id]}}))))

[petterik]

Unsure how important this is when there'll be ways to expand the queries with data such as #9