Refactor pv printing

Also fix the case which is currently printing depth 0.

fixes #5019
closes https://github.com/official-stockfish/Stockfish/pull/5020

No functional change

src/uci.h

@@ -19,7 +19,6 @@
 #ifndef UCI_H_INCLUDED
 #define UCI_H_INCLUDED
 
-#include <cstdint>
 #include <iostream>
 #include <string>
 #include <unordered_map>
@@ -37,10 +36,6 @@ namespace Eval::NNUE {
 enum NetSize : int;
 }
 
-namespace Search {
-class Worker;
-}
-
 class Move;
 enum Square : int;
 using Value = int;
@@ -55,12 +50,6 @@ class UCI {
     static std::string value(Value v);
     static std::string square(Square s);
     static std::string move(Move m, bool chess960);
-    static std::string pv(const Search::Worker& workerThread,
-                          TimePoint             elapsed,
-                          uint64_t              nodesSearched,
-                          uint64_t              tb_hits,
-                          int                   hashfull,
-                          bool                  rootInTB);
     static std::string wdl(Value v, int ply);
     static Move        to_move(const Position& pos, std::string& str);