MINOR: cfgcond: implements openssl_version_atleast and openssl_version_before

Implements a way of checking the running openssl version:

If the OpenSSL support was not compiled within HAProxy it will returns a
error, so it's recommanded to do a SSL feature check before:

	$ ./haproxy -cc 'feature(OPENSSL) && openssl_version_atleast(0.9.8zh) && openssl_version_before(3.0.0)'

This will allow to select the SSL reg-tests more carefully.

include/haproxy/cfgcond-t.h

@@ -50,6 +50,8 @@ enum cond_predicate {
 	CFG_PRED_STRNEQ,          // "strneq"
 	CFG_PRED_VERSION_ATLEAST, // "version_atleast"
 	CFG_PRED_VERSION_BEFORE,  // "version_before"
+	CFG_PRED_OSSL_VERSION_ATLEAST, // "openssl_version_atleast"
+	CFG_PRED_OSSL_VERSION_BEFORE,  // "openssl_version_before"
 };
 
 /* types for condition terms */

include/haproxy/tools.h

@@ -1093,4 +1093,8 @@ static inline void update_char_fingerprint(uint8_t *fp, char prev, char curr)
 	fp[32 * from + to]++;
 }
 
+
+/* compare the current OpenSSL version to a string */
+int openssl_compare_current_version(const char *version);
+
 #endif /* _HAPROXY_TOOLS_H */