Low-level "generic" signal creator for creating signals of any "kind".
Takes a single map of options [2] with compile-time keys.

Default  kind: `:generic` (feel free to change!)
Default level: `:info`
Returns:
  - If given `:run` form: unconditionally returns run value, or rethrows run error.
  - Otherwise: returns true iff signal was created (allowed by filtering).

When filtering conditions are met [4], creates a Telemere signal [3] and
dispatches it to registered handlers for processing (e.g. writing to
console/file/queue/db, etc.).

Generic signals are fairly low-level and useful mostly for library authors or
advanced users writing their own wrapper macros. NB see `keep-callsite` for
preserving callsite coords when wrapping Telemere macros like `signal!`.

Regular users will typically prefer one of the higher-level signal creators
optimized for ease-of-use in common cases [1].

Tips:

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

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[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.)