Make auth-source-pass behave more like other backends

Make auth-source-pass behave more like other backends

* lisp/auth-source-pass.el (auth-source-pass-extra-query-keywords): Add
new option to bring search behavior more in line with other backends.
(auth-source-pass-search): Add new keyword params `max' and `require'
and consider new option `auth-source-pass-extra-query-keywords' for
dispatch.
(auth-source-pass--match-regexp, auth-source-pass--retrieve-parsed,
auth-source-pass--match-parts): Add supporting variable and helpers.
(auth-source-pass--build-result-many,
auth-source-pass--find-match-many): Add "-many" variants for existing
workhorse functions.
* test/lisp/auth-source-pass-tests.el: Require `ert-x'.
(auth-source-pass-can-start-from-auth-source-search): Ensure
`auth-source-pass-extra-query-keywords' is enabled around test body.
(auth-source-pass-extra-query-keywords--wild-port-miss-netrc,
auth-source-pass-extra-query-keywords--wild-port-miss,
auth-source-pass-extra-query-keywords--wild-port-hit-netrc,
auth-source-pass-extra-query-keywords--wild-port-hit,
auth-source-pass-extra-query-keywords--wild-port-req-miss-netrc,
auth-source-pass-extra-query-keywords--wild-port-req-miss,
auth-source-pass-extra-query-keywords--netrc-akib,
auth-source-pass-extra-query-keywords--akib,
auth-source-pass-extra-query-keywords--netrc-host,
auth-source-pass-extra-query-keywords--host,
auth-source-pass-extra-query-keywords--baseline,
auth-source-pass-extra-query-keywords--port-type,
auth-source-pass-extra-query-keywords--hosts-first,
auth-source-pass-extra-query-keywords--ambiguous-user-host,
auth-source-pass-extra-query-keywords--suffixed-user,
auth-source-pass-extra-query-keywords--user-priorities): Add
juxtaposed netrc and extra-query-keywords pairs to demo optional
extra-compliant behavior.
* doc/misc/auth.texi: Add option
`auth-source-pass-extra-query-keywords' to auth-source-pass section.
* etc/NEWS: Mention `auth-source-pass-extra-query-keywords' in Emacs
29.1 package changes section.  (Bug#58985.)

Special thanks to Akib Azmain Turja <akib@disroot.org> for helping
improve this patch.