Just implement support to use CURLOPT_CAINFO_BLOB with bearssl.
Also fixed bearssl support building error on hostname = NULL; while having const char * const hostname = SSL_HOST_NAME();

There are four ways to implement support:

• have one function with parsing cert file from the buffer and two ways to get buffer. I don't want to read an entire file into memory so denied
• have two big functions with similar code buf from different sources. Too big code repeat so denied
• parse cert file iteratively while having state struct. Need to split function into some struct, init(), dispose() and update(). Denied because of complexity
• have some switches in the cert parsing function. The easiest way with a minimum amount of modification. Implemented this way