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/DetectCrash_test.cpp

@@ -2,7 +2,7 @@
 
 #include <exception>
 
-namespace ripple {
+namespace xrpl {
 namespace test {
 
 struct DetectCrash_test : public beast::unit_test::suite
@@ -25,4 +25,4 @@ struct DetectCrash_test : public beast::unit_test::suite
 BEAST_DEFINE_TESTSUITE_MANUAL(DetectCrash, basics, beast);
 
 }  // namespace test
-}  // namespace ripple
+}  // namespace xrpl