Without CA certificates the HTTP client will unable to verify server's
certificate, so the only way to perform an HTTPS request would be use
the `verify_peer = false` option -- disable certificate validation at
all.

The runtime search of system CA bundle/certificates was unintentionally
disabled in 2.10.0 (PR #7119). The patch enabled is back.

The main motivation behind the runtime search is difference in paths on
different systems. Since we ship Tarantool Enterprise Edition as
executable with ability to run on different Linux distributions, we
can't choose one particular path at build time. See details in #5746.

The `CURL_CA_BUNDLE_SET` and `CURL_CA_PATH_SET` options were removed,
because they are not 'real' curl configuration options, but rather
cached values to don't repeat file/directory search at re-configuration.
It looks as internal logic of Curl's CMake script.

NO_DOC=Lack of proper HTTPS support is definitely broken behavior, there
       is no sense to document it or the opposite.
NO_TEST=A simple test would require to send a request to external host.
        It would not work without internet connection or in a sandbox.
        Such test also would be unstable and would fail from time to
        time due to network conditions. I verified the patch manually. I
        have an idea to add more thorough http client testing later.

Fixes #7372