missing checks for debug attributes lead to TypeErrors on Execution

[GitMensch]

as seen in fredericbonnet/cmake-test-explorer#71 - but this also happens when you comment out the target attribute in a previously working debug configuration:

TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string. Received undefined
at new NodeError (node:internal/errors:399:5)
at validateString (node:internal/validators:163:11)
at Object.isAbsolute (node:path:1157:5)
at MI2.load (/workspace/.vscode-remote/extensions/webfreak.debug-0.26.1-universal/out/src/backend/mi2/mi2.js:65:19)
at GDBDebugSession.launchRequest (/workspace/.vscode-remote/extensions/webfreak.debug-0.26.1-universal/out/src/gdb.js:52:29)
at GDBDebugSession.dispatchRequest (/workspace/.vscode-remote/extensions/webfreak.debug-0.26.1-universal/node_modules/vscode-debugadapter/lib/debugSession.js:378:22)
at GDBDebugSession.handleMessage (/workspace/.vscode-remote/extensions/webfreak.debug-0.26.1-universal/node_modules/vscode-debugadapter/lib/protocol.js:61:18)
at GDBDebugSession._handleData (/workspace/.vscode-remote/extensions/webfreak.debug-0.26.1-universal/node_modules/vscode-debugadapter/lib/protocol.js:155:34)
at Socket.<anonymous> (/workspace/.vscode-remote/extensions/webfreak.debug-0.26.1-universal/node_modules/vscode-debugadapter/lib/protocol.js:80:44)
at Socket.emit (node:events:513:28)

Resolution: check attributes in the launchRequest and give a clear error message if something mandatory is missing or if there's a type mismatch.