Make it easier to switch to CE version of our official images
Currently in order to use the CE images you need to swap several repositories, documented here: https://gitlab.com/charts/gitlab/blob/3d4ad75e4cc0cd43f6142640a17aecf87dc3a41b/doc/installation/deployment.md#deploy-the-community-edition
This causes issues when we update the list, like when we split workhorse out, because user's end up with a mix of EE and CE images until they find and update the EE ones. During this past release we saw several responses from the community regarding this issue (https://gitlab.com/charts/gitlab/issues/715, https://gitlab.com/charts/gitlab/issues/711, https://gitlab.com/charts/gitlab/issues/694)
It would be a nicer user experience if we made the chart aware of both sets of images, CE, and EE, and allowed the user to swap to CE with just a single setting.