Adjust tctl sso commands to new teams_to_roles field.

[Tener]

With recent addition of teams_to_roles field to Github auth connectors, some adjustments are needed:

1. Make tctl sso configure github populate teams_to_roles field
2. Add a new SSO diagnostic field to carry teams_to_roles mapping
3. Make tctl sso test aware of teams_to_roles mapping from diagnostic field
4. Populate diagnostic field in relevant part of code.

This PR supersedes code changes in #13148.

[xacrimon]

Approved but one question. Do we need to have any additional changes to support changing/printing/anything else to the existing but deprecated teams_to_logins field since that may still be in use?

[Tener]

Approved but one question. Do we need to have any additional changes to support changing/printing/anything else to the existing but deprecated teams_to_logins field since that may still be in use?

With respect to tctl sso ... commands? No further changes are needed as far as I can tel.

In general though? I think these 2 places may need updating:

teleport/tool/tctl/common/collection.go

Lines 391 to 399 in 40200e8

	func (c *githubCollection) writeText(w io.Writer) error {
	t := asciitable.MakeTable([]string{"Name", "Teams To Logins"})
	for _, conn := range c.connectors {
	t.AddRow([]string{conn.GetName(), formatTeamsToLogins(
	conn.GetTeamsToLogins())})
	}
	_, err := t.AsBuffer().WriteTo(w)
	return trace.Wrap(err)
	}

teleport/lib/auth/auth_with_roles.go

Lines 2562 to 2579 in a61d38a

	func (a *ServerWithRoles) checkGithubConnector(connector types.GithubConnector) error {
	mapping := connector.GetTeamsToLogins()
	for _, team := range mapping {
	if len(team.KubeUsers) != 0 || len(team.KubeGroups) != 0 {
	return trace.BadParameter("since 6.0 teleport uses teams_to_logins to reference a role, use it instead of local kubernetes_users and kubernetes_groups ")
	}
	for _, localRole := range team.Logins {
	_, err := a.GetRole(context.TODO(), localRole)
	if err != nil {
	if trace.IsNotFound(err) {
	return trace.BadParameter("since 6.0 teleport uses teams_to_logins to reference a role, role %q referenced in mapping for organization %q is not found", localRole, team.Organization)
	}
	return trace.Wrap(err)
	}
	}
	}
	return nil
	}

I feel like those 2 changes are out of scope of this PR... There may also be other places that need changing? I'm not sure though.