We need to support the user creating templates with the extended support repositories

• In creation wizard, if user has feature, have option to select extended release
• Update repository parameters to include extended release information, using features api to filter out items the user doesn't have a subscription to
• Do not allow selection of normal appstream and baseos if extended release is selected
• Add warning in template creation to set system release version for extended release. Could use an “information” banner
• In use template, if template is extended release, show information about how to set system repo version
• Depending on how the blocking task is implemented, this may require an API change for selecting the template version or adding an extended_release_version column to the templates table
• Update template api/model to support storing a version & extended release
• Update template list UI to include minor version in version column and extended release name