yuzu: Move compatibility list specifics to their own source files

Lets us keep the generic portions of the compatibility list code
together, and allows us to introduce a type alias that makes it so we
don't need to type out a very long type declaration anymore, making the
immediate readability of some code better.

src/citra_qt/compatibility_list.cpp

@@ -0,0 +1,18 @@
+// Copyright 2018 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+
+#include <fmt/format.h>
+
+#include "citra_qt/compatibility_list.h"
+
+CompatibilityList::const_iterator FindMatchingCompatibilityEntry(
+    const CompatibilityList& compatibility_list, u64 program_id) {
+    return std::find_if(compatibility_list.begin(), compatibility_list.end(),
+                        [program_id](const auto& element) {
+                            std::string pid = fmt::format("{:016X}", program_id);
+                            return element.first == pid;
+                        });
+}