Normalise SSL certificate's issuer and subject

[jcamiel]

We're exposing the subject and issuer directly from libcurl. In the certificate, these properties are list of pair of key-value. Through libcurl, these lists are serialized to a string:

Example:

vec![("C","US"),("O","Google Trust Services LLC"),("CN","GTS Root R1"))] =>
"C = US, O = Google Trust Services LLC, CN = GTS Root R1"

We should normalize the serialization (use 'A = B' or 'A=B') to always have the same issuer/
subject given a certain certificate. Actually the value can differ on different platforms, for
a given certificate.

See:

• integration/hurl/ssl/cacert_to_json.out.pattern
• https://curl.se/mail/lib-2024-06/0013.html