doc: add clarification for exception behaviour

Document current behaviour where some methods can be called
when an exception is pending, while others cannot and explain
the behaviour.

PR-URL: https://github.com/nodejs/node/pull/25339
Refs: https://github.com/nodejs/abi-stable-node/issues/356


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>