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/libxrpl/ledger/ReadView.cpp

@@ -1,6 +1,6 @@
 #include <xrpl/ledger/ReadView.h>
 
-namespace ripple {
+namespace xrpl {
 
 ReadView::sles_type::sles_type(ReadView const& view) : ReadViewFwdRange(view)
 {
@@ -68,4 +68,4 @@ makeRulesGivenLedger(
     return Rules(presets);
 }
 
-}  // namespace ripple
+}  // namespace xrpl