* Add support for `cause:` argument to `Fiber#raise` and `Thread#raise`.

The implementation behaviour is consistent with `Kernel#raise` and
`Exception#initialize` methods, allowing the `cause:` argument to be
passed to `Fiber#raise` and `Thread#raise`. This change ensures that
the `cause:` argument is handled correctly, providing a more consistent
and expected behavior when raising exceptions in fibers and threads.

[Feature #21360]

* Shared specs for Fiber/Thread/Kernel raise.

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Co-authored-by: Samuel Williams <samuel.williams@shopify.com>

This is a static function only called in two places (rb_to_id and
rb_to_symbol), and in both places, both symbols and strings are
allowed.  This makes the error message consistent with rb_check_id
and rb_check_symbol.

Fixes [Bug #20607]

Previously, a TypeError was not raised if there were no thread
variables, because the conversion to symbol was done after that
check.  Convert to symbol before checking for whether thread
variables are set to make the behavior consistent.

Fixes [Bug #20606]

Accecpt the same arguments as `caller` and `caller_locations`.