Add support for `CURLOPT_CAINFO_BLOB` `CURLOPT_PROXY_CAINFO_BLOB` to the
rustls TLS backend. Multiple certificates in a single PEM string are
supported just like OpenSSL does with this option.
This is compatible at least with rustls-ffi 0.8+ which is our new
minimum version anyway.
I was able to build and run this on Windows, pulling trusted certs from
the system and then add them to rustls by setting
`CURLOPT_CAINFO_BLOB`. Handy!
Closes#8255
Make all libcurl related options use .nf (no fill) for the SYNOPSIS
section - for consistent look. roffit then renders that section using
<pre> (monospace font) in html for the website.
Extended manpage-syntax (test 1173) with a basic check for it.
Closes#8062