doc: added napi_get_value_string_latin1

* Reordered string functions alphabetically
* Fixed a typo in napi_get_value_string_utf8

Backport-PR-URL: https://github.com/nodejs/node/pull/19447
PR-URL: https://github.com/nodejs/node/pull/14678
Fixes: https://github.com/nodejs/node/issues/14397
Refs: https://github.com/nodejs/node/issues/14256


Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>