LibLocale: Move locale source files to the LibLocale folder

These are still included in LibUnicode, but this updates their location
and the include paths of other files which include them.

Userland/Libraries/LibUnicode/RelativeTimeFormat.h

@@ -1,39 +0,0 @@
-/*
- * Copyright (c) 2022, Tim Flynn <trflynn89@serenityos.org>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#pragma once
-
-#include <AK/Optional.h>
-#include <AK/StringView.h>
-#include <AK/Vector.h>
-#include <LibUnicode/Forward.h>
-#include <LibUnicode/Locale.h>
-
-namespace Locale {
-
-// These are just the subset of fields in the CLDR required for ECMA-402.
-enum class TimeUnit {
-    Second,
-    Minute,
-    Hour,
-    Day,
-    Week,
-    Month,
-    Quarter,
-    Year,
-};
-
-struct RelativeTimeFormat {
-    PluralCategory plurality;
-    StringView pattern;
-};
-
-Optional<TimeUnit> time_unit_from_string(StringView time_unit);
-StringView time_unit_to_string(TimeUnit time_unit);
-
-Vector<RelativeTimeFormat> get_relative_time_format_patterns(StringView locale, TimeUnit time_unit, StringView tense_or_number, Style style);
-
-}