Workspace-level launch configurations crash if cwd is not specified

[mathieuchopstm]

Describe the bug
If a launch configuration located in the VS Code workspace file (instead of the usual <folder>/.vscode/launch.json) does not specify cwd, attempting to launch a debug session will fail with a Cannot read property 'uri' of undefined error popup.

The bug seems to be located in resolveDebugConfigurationWithSubstitutedVariables:

cortex-debug/src/frontend/configprovider.ts

Lines 202 to 206 in 8210ae4

	public resolveDebugConfigurationWithSubstitutedVariables(
	folder: vscode.WorkspaceFolder | undefined,
	config: vscode.DebugConfiguration,
	token?: vscode.CancellationToken
	): vscode.ProviderResult<vscode.DebugConfiguration> {

The buggy statement appears to be the very first of the function:

cortex-debug/src/frontend/configprovider.ts

Line 207 in 8210ae4

let cwd = config.cwd || folder.uri.fsPath;

Note how the uri member is accessed without validity checks, despite it being vscode.WorkspaceFolder | undefined (folder?.uri.fsPath should probably have been used instead).

To Reproduce
Steps to reproduce the behavior:

1. Create a VS Code Workspace
2. Add a launch section in the .code-workspace file
3. Create a cortex-debug launch configuration
4. Making sure that cwd is not present in the launch configuration, attempt launch
5. See issue: Cannot read property 'uri' of undefined
6. Add cwd to launch configuration, attempt launch
7. See that the debug session starts properly

Expected behavior

If cwd is not provided, rather than crashing, the extension should display an error message, as is done a few lines below the buggy code mentioned earlier.

cortex-debug/src/frontend/configprovider.ts

Lines 211 to 214 in 8210ae4

	config.cwd = cwd;
	if (!fs.existsSync(cwd)) {
	vscode.window.showWarningMessage(`Invalid "cwd": "${cwd}". Many operations can fail. Trying to continue`);
	}

Screenshots

N/A

Environment:

• Cortex-Debug: v1.12.1
• OS: Linux Ubuntu 22.04 LTS
• VSCode: 1.94.2
• GDB Version: N/A
• Compiler Toolchain Version: N/A

Additional context

N/A