Import YEEP-144 library 1.2 sources

Source-only snapshot of the 1.2 release. Drivers/ (the vendored ST HAL and
CMSIS) is excluded at 173 MB; fetch it from STMicroelectronics/STM32CubeH5 to
build.

.vscode/c_cpp_properties.json

@@ -0,0 +1,8 @@
+{
+    "configurations": [
+        {
+            "name": "STM32",
+            "compileCommands": "${workspaceFolder}/build/Debug/compile_commands.json"
+        }
+    ]
+}