Ability to disable/hide the identity provider on the selection page

1. Proposed title of this feature request

 Ability to customize the identity provider list on the selection page.

2. What is the nature and description of the request?

 The customer would like to disable/hide an identity provider from the list of choices on the OAuth identity provider selection screen. 

3. Why does the customer need this? (List the business requirements here)

 Customer would like to avoid confusion for normal users when they log into any Openshift console with Oauth (using LDAP), but still, want's the fallback option of logging into the cluster with either kube:admin or an HTPasswd user, in case the LDAP service is unavailable.

4. List any affected packages or components.

 OpenShift OAuth Identity Provider Console Page.

As of now, when users try to login using the web console, they must select the identity provider before. It is inbuilt in the code to show the entire list of identity providers:

$ oc adm create-provider-selection-template | less
....
    {{ range $provider := .Providers }}
      <div>
        {{ if eq $provider.Name "anypassword" }}
          <a href="{{$provider.URL}}">Log in</a> with any username and password
        {{ else }}
          <a href="{{$provider.URL}}">{{$provider.Name}}</a>
        {{ end }}
      </div>
    {{ end }}
.....