Respect some spaces in auth-source-pass--match-regexp

Respect some spaces in auth-source-pass--match-regexp

* lisp/auth-source-pass.el (auth-source-pass--match-regexp): Allow an
entry's host and user fields to contain spaces, just like other
backends do.
* lisp/erc/erc-compat.el
(erc-compat--29-auth-source-pass--retrieve-parsed): Change regexp to
allow spaces in host and user components of file names.
* test/lisp/auth-source-pass-tests.el (auth-source-pass-any-host):
Silence warning message re wildcards emitted by
`auth-source-pass-search'.
(auth-source-pass-extra-query-keywords--suffixed-user): Add spaces
to users and hosts of some example entries.  (Bug#58985.)