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.

tests/conan/src/example.cpp

@@ -5,6 +5,6 @@
 int
 main(int argc, char const** argv)
 {
-    std::printf("%s\n", ripple::BuildInfo::getVersionString().c_str());
+    std::printf("%s\n", xrpl::BuildInfo::getVersionString().c_str());
     return 0;
 }