common/peg : refactor until gbnf grammar generation (#24839)

* common/peg : refactor until gbnf grammar into an ac automaton

* cont : add a test with multiple strings

* cont : pad state with 0s so rules line up

* cont : clean up comments

* cont : use set everywhere

* cont : inline state num string padding

* cont : add a ref to PR

* cont : fix regression in server-tools.cpp

tools/server/server-tools.cpp

@@ -11,6 +11,7 @@
 #include <cstring>
 #include <climits>
 #include <algorithm>
+#include <unordered_set>
 
 namespace fs = std::filesystem;