Make some of the TLS options configurable

This commit makes some of the TLS options that are used for
impersonation configurable via libcurl options and command line flags to
curl-impersonate. The goal is to give more flexibility in configuring
the TLS extensions instead of hardcoding everything into the binary.
This will enable using the same binary for impersonating different
browsers (e.g. Safari).

The following options are now present:
* CURLOPT_SSL_EC_CURVES and the '--curves' flag are now usable. These
were present in the upstream curl but only for OpenSSL builds. This
commit also enables them for BoringSSL. They configure TLS extension
'supported_groups' (no. 10).
* CURLOPT_SSL_ENABLE_NPN and the '--no-npn' flags are usable. These were
present in the upstream curl but were disabled in a previous commit by
commenting out the relevant code (as Chrome disables NPN). They now work
and the wrapper scripts use the '--no-npn' flag.
* CURLOPT_SSL_ENABLE_ALPS and the '--alps' flag were added. These
control the ALPS TLS extension that Chrome uses.
* CURLOPT_SSL_SIG_HASH_ALGS and the '--signature-hashes' option were
added. These control the clien't list of supported signature & hash
algorithms, i.e. TLS extension 'signature_algorithms' (no. 13).

chrome/curl_chrome98

@@ -20,5 +20,6 @@ dir=`echo "$0" | sed 's%/[^/]*$%%'`
     -H 'Sec-Fetch-Dest: document' \
     -H 'Accept-Encoding: gzip, deflate, br' \
     -H 'Accept-Language: en-US,en;q=0.9' \
-    --http2 --false-start --tlsv1.2 --compressed \
+    --http2 --false-start --compressed \
+    --tlsv1.2 --no-npn --alps \
     $@