refactor: Rename ripple namespace to xrpl (#5982)

This change renames all occurrences of `namespace ripple` and `ripple::` to `namespace xrpl` and `xrpl::`, respectively, as well as the names of test suites. It also provides a script to allow developers to replicate the changes in their local branch or fork to avoid conflicts.

src/libxrpl/net/HTTPClient.cpp

@@ -12,7 +12,7 @@
 
 #include <optional>
 
-namespace ripple {
+namespace xrpl {
 
 static std::optional<HTTPClientSSLContext> httpClientSSLContext;
 
@@ -605,4 +605,4 @@ HTTPClient::request(
     client->request(bSSL, deqSites, setRequest, timeout, complete);
 }
 
-}  // namespace ripple
+}  // namespace xrpl