oe-selftest: devtool ide-sdk cover vscode remote debugging

oe-selftest: devtool ide-sdk cover vscode remote debugging

This adds more test coverage for devtool ide-sdk, with VSCode. The cmake
test case has now a full remote debugging test on Qemu. The test checks
the generated launch.json and tasks.json files, starts gdbserver and
connects to it. The test verifies breakpoints, variables and source file
listing.

Signed-off-by: Adrian Freihofer <adrian.freihofer@siemens.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>