Currently {{select-keys}} on an {{HMap}} returns a {{Map}} with unions for keys and values.
=> (t/cf {:foo 1, :bar "2", :baz \3})
[(HMap :mandatory {:baz (Value \3), :bar (Value "2"), :foo (Value 1)} :complete? true) {:then tt, :else ff}]
=> (t/cf (select-keys {:foo 1, :bar "2", :baz \3}
[:foo :bar]))
(t/Map (U (Value :baz) (Value :foo) (Value :bar)) (U (Value 1) (Value \3) (Value "2")))
This results in type errors when {{select-keys}} is used to remove extra keys from an {{HMap}}.
Expected behaviour: {{select-keys}} should return an {{HMap}} with a subset of the {{:mandatory}} keys of its input {{HMap}}.
