string_util: Remove StringFromFormat() and related functions

Given we utilize fmt, we don't need to provide our own functions for formatting anymore

src/citra_qt/bootmanager.cpp

@@ -4,6 +4,8 @@
 #include <QScreen>
 #include <QWindow>
 
+#include <fmt/format.h>
+
 #include "citra_qt/bootmanager.h"
 #include "common/microprofile.h"
 #include "common/scm_rev.h"
@@ -103,8 +105,8 @@ private:
 GRenderWindow::GRenderWindow(QWidget* parent, EmuThread* emu_thread)
     : QWidget(parent), child(nullptr), emu_thread(emu_thread) {
 
-    std::string window_title = Common::StringFromFormat("Citra %s| %s-%s", Common::g_build_name,
-                                                        Common::g_scm_branch, Common::g_scm_desc);
+    std::string window_title = fmt::format("Citra {} | {}-{}", Common::g_build_name,
+                                           Common::g_scm_branch, Common::g_scm_desc);
     setWindowTitle(QString::fromStdString(window_title));
 
     InputCommon::Init();

src/citra_qt/game_list.cpp

@@ -20,6 +20,7 @@
 #include <QThreadPool>
 #include <QToolButton>
 #include <QTreeView>
+#include <fmt/format.h>
 #include "citra_qt/game_list.h"
 #include "citra_qt/game_list_p.h"
 #include "citra_qt/main.h"

src/citra_qt/main.cpp

@@ -14,6 +14,7 @@
 #include <QtConcurrent/QtConcurrentRun>
 #include <QtGui>
 #include <QtWidgets>
+#include <fmt/format.h>
 #include "citra_qt/aboutdialog.h"
 #include "citra_qt/applets/swkbd.h"
 #include "citra_qt/bootmanager.h"