See https://github.com/docker/cli/pull/4599 and
https://github.com/docker/cli/pull/4769.
Since we switched to using the cobra command context instead of
`appcontext`, we need to set up the signal handling that was being
provided by `appcontext`, as well as configuring the context with
the OTEL tracing utilities also used by `appcontext`.
This commit introduces `cobrautil.ConfigureContext` which implements
the pre-existing signal handling logic from `appcontext` and cancels
the command's context when a signal is received, as well as doing
the relevant OTEL config.
Signed-off-by: Laura Brehm <laurabrehm@hey.com>
