[lldb-dap] Add stdio redirection for integrated and external terminals (#161089)
This patch extends stdio redirection support to integrated and external
terminals. Currently, these cases are not covered by the standard logic
because `attach` is used instead of `launch`. To be honest,
`runInTerminal` in
[VSCode](https://github.com/microsoft/vscode/blob/main/src/vs/workbench/contrib/debug/node/terminals.ts#L188)
request supports `>` and `<` for redirection, but not `2>`. We could use
the `argsCanBeInterpretedByShell` option to use full power of shell,
however it requieres proper escaping of arguments on lldb-dap side. So,
I think it will be better to have the only one option to control stdio
redirection that works consistently across all console modes.
Also, fixed a small typo in a comparison that was leading to
out-of-bound access, and added `null` as a possible value for `stdio`
array in package.json.