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/test/rpc/ServerInfo_test.cpp

@@ -8,7 +8,7 @@
 
 #include <boost/format.hpp>
 
-namespace ripple {
+namespace xrpl {
 
 namespace test {
 
@@ -162,7 +162,7 @@ admin = 127.0.0.1
     }
 };
 
-BEAST_DEFINE_TESTSUITE(ServerInfo, rpc, ripple);
+BEAST_DEFINE_TESTSUITE(ServerInfo, rpc, xrpl);
 
 }  // namespace test
-}  // namespace ripple
+}  // namespace xrpl