Core/Cryptography: Move the SHA1 calculate helper to the SHA1 header

src/common/Cryptography/SHA1.h

@@ -46,5 +46,8 @@ class TC_COMMON_API SHA1Hash
         SHA_CTX mC;
         uint8 mDigest[SHA_DIGEST_LENGTH];
 };
-#endif
 
+/// Returns the SHA1 hash of the given content as hex string.
+TC_COMMON_API std::string CalculateSHA1Hash(std::string const& content);
+
+#endif