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/protocol/BuildInfo_test.cpp

@@ -1,7 +1,7 @@
 #include <xrpl/beast/unit_test.h>
 #include <xrpl/protocol/BuildInfo.h>
 
-namespace ripple {
+namespace xrpl {
 
 class BuildInfo_test : public beast::unit_test::suite
 {
@@ -95,5 +95,5 @@ public:
     }
 };
 
-BEAST_DEFINE_TESTSUITE(BuildInfo, protocol, ripple);
-}  // namespace ripple
+BEAST_DEFINE_TESTSUITE(BuildInfo, protocol, xrpl);
+}  // namespace xrpl