Add hal_wch based on the 'ch32v003fun' project

This is used for WCH chips including the CH32V003.

Based on the following commit,

cnlohr/ch32v003fun@d8fe188769be78219

LICENSE

@@ -0,0 +1,26 @@
+MIT License
+
+Copyright (c) 2023-2024 CNLohr <[email protected]>, et. al.
+Copyright (c) 2021 Nanjing Qinheng Microelectronics Co., Ltd.
+Copyright (c) 2023-2024 E. Brombaugh
+Copyright (c) 2023-2024 A. Mandera
+Copyright (c) 2005-2020 Rich Felker, et al.
+Copyright (c) 2013,2014 Michal Ludvig <[email protected]>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.