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/basics/IntrusiveShared_test.cpp

@@ -17,7 +17,7 @@
 #include <thread>
 #include <variant>
 
-namespace ripple {
+namespace xrpl {
 namespace tests {
 
 /**
@@ -887,6 +887,6 @@ public:
     }
 };  // namespace tests
 
-BEAST_DEFINE_TESTSUITE(IntrusiveShared, basics, ripple);
+BEAST_DEFINE_TESTSUITE(IntrusiveShared, basics, xrpl);
 }  // namespace tests
-}  // namespace ripple
+}  // namespace xrpl