Assorted cleanups

- fix naming convention for `workingDirectory`
- use type alias for `EvalFiles` everywhere
- move `ponderMode` into `LimitsType`
- move limits parsing into standalone static function

closes https://github.com/official-stockfish/Stockfish/pull/5098

No functional change

src/uci.h

@@ -21,7 +21,6 @@
 
 #include <iostream>
 #include <string>
-#include <unordered_map>
 
 #include "evaluate.h"
 #include "misc.h"
@@ -29,13 +28,10 @@
 #include "thread.h"
 #include "tt.h"
 #include "ucioption.h"
+#include "search.h"
 
 namespace Stockfish {
 
-namespace Eval::NNUE {
-enum NetSize : int;
-}
-
 class Move;
 enum Square : int;
 using Value = int;
@@ -53,11 +49,12 @@ class UCI {
     static std::string wdl(Value v, int ply);
     static Move        to_move(const Position& pos, std::string& str);
 
-    const std::string& workingDirectory() const { return cli.workingDirectory; }
+    static Search::LimitsType parse_limits(const Position& pos, std::istream& is);
 
-    OptionsMap options;
+    const std::string& working_directory() const { return cli.workingDirectory; }
 
-    std::unordered_map<Eval::NNUE::NetSize, Eval::EvalFile> evalFiles;
+    OptionsMap            options;
+    Eval::NNUE::EvalFiles evalFiles;
 
    private:
     TranspositionTable tt;