toolchain: v38; clangd as default language server (#3774)

* libs: removed cxxheaderparser submodule, expecting one from toolchain
* toolchain: v38
* vscode: now using clangd from toolchain
* vscode: clangd path in config is now generated by fbt
* vscode, fbt: improved clangd path generation
* fbt: fixed LANG_SERVER handling; switched to clangd as default
* vscode: removed deprecated options from config
* ufbt: project template: updated clang-format, added clangd config
* ufbt: now using clangd as default language server
* ufbt: now using clangd as default language server

scripts/ufbt/project_template/.vscode/settings.json

@@ -5,7 +5,6 @@
 {
     "cortex-debug.enableTelemetry": false,
     "cortex-debug.variableUseNaturalFormat": false,
-    "cortex-debug.showRTOS": true,
     "cortex-debug.armToolchainPath": "@UFBT_TOOLCHAIN_ARM_TOOLCHAIN_DIR@",
     "cortex-debug.openocdPath": "@UFBT_TOOLCHAIN_OPENOCD@",
     "cortex-debug.gdbPath": "@UFBT_TOOLCHAIN_GDB_PY@",
@@ -16,9 +15,15 @@
         "SConstruct": "python",
         "*.fam": "python"
     },
-    "cortex-debug.registerUseNaturalFormat": false,
     "python.analysis.typeCheckingMode": "off",
     "[python]": {
         "editor.defaultFormatter": "ms-python.black-formatter"
-    }
+    },
+    "clangd.path": "@UFBT_TOOLCHAIN_CLANGD@",
+    "clangd.arguments": [
+        "--query-driver=**/arm-none-eabi-*",
+        "--compile-commands-dir=${workspaceFolder}/.vscode",
+        "--clang-tidy",
+        "--header-insertion=never"
+    ]
 }