This commit modifies the operator helm chart values to bring the newly
added `loginServer` field to the top level. We felt as though it was a bit
confusing to be at the `operatorConfig` level as this value modifies the
behaviour or the operator, api server & all resources that the operator
manages.
Updates https://github.com/tailscale/corp/issues/29847
Signed-off-by: David Bond <davidsbond93@gmail.com>