"Error" signal creator, emphasizing (optional id) + error (Exception, etc.).

Default  kind: `:error`
Default level: `:error`
Returns:
  ALWAYS (unconditionally) returns the given error, so can conveniently be
  wrapped by `throw`: (throw (error! (ex-info ...)), etc.

Examples:

  (throw (error!         (ex-info "MyEx" {}))) ; %> {:kind :error, :level :error, :error <MyEx> ...}
  (throw (error! ::my-id (ex-info "MyEx" {}))) ; %> {... :id ::my-id ...}
  (throw
    (error!
      {:let  [x "x"] ; Available to `:data` and `:msg`
       :data {:x x}
       :msg  ["My message:" x]}

      (ex-info "MyEx" {}))) ; %> {... :data {x "x"}, :msg_ "My msg: x" ...}

Tips:

  - Test using `with-signal`: (with-signal (error! ...)).
  - Supports the same options [2] as other signals [1].

  - `error` arg is a platform error (`java.lang.Throwable` or `js/Error`).

----------------------------------------------------------------------
[1] See `help:signal-creators` - (`signal!`, `log!`, `event!`, ...)
[2] See `help:signal-options`  - {:keys [kind level id data ...]}
[3] See `help:signal-content`  - {:keys [kind level id data ...]}
[4] See `help:signal-filters`  - (by ns/kind/id/level, sampling, etc.)