Nodule to represent annotations on types.

`type t`````
`include sig ... end`
`val compare : t ‑> t ‑> int`
`val const : InferModules.AnnotatedSignature.annotation ‑> bool ‑> InferModules.TypeOrigin.t ‑> t`
`val descr_origin : InferIR.Tenv.t ‑> t ‑> InferModules.TypeErr.origin_descr`

Human-readable description of the origin of a nullable value.

`val from_item_annotation : InferIR.Annot.Item.t ‑> InferModules.TypeOrigin.t ‑> t`
`val get_origin : t ‑> InferModules.TypeOrigin.t`
`val get_value : InferModules.AnnotatedSignature.annotation ‑> t ‑> bool`
`val join : t ‑> t ‑> t option`
`val origin_is_fun_library : t ‑> bool`
`val set_value : InferModules.AnnotatedSignature.annotation ‑> bool ‑> t ‑> t`
`val to_string : t ‑> string`
`val with_origin : t ‑> InferModules.TypeOrigin.t ‑> t`