Wrap lifecycle hooks and other operations in `start`/`stop` log messages

Recently Codespaces has gotten several reports where the root cause was difficult to debug. It would be useful if the logs emitted from the CLI clearly mark the start and end of a lifecycle script - perhaps like the following:

```
--- starting to execute 'postCreateCommand' script 'foo'

... foo output...

--- 'postCreateCommand' script 'foo' exited code 0
```

This would be particularly helpful in cases where `foo` does not emit any logs.