Promote features to unlicensed users

Resources

FE @timzallmann

As part of making EE the default download on GitLab and simplifying the experience, we need to promote EE features when there is no license for that particular feature.

Proposal

• For each relevant paid feature, we need to promote trial or license activation for regular EE on-prem sites
• For GitLab.com the feature promotion needs to go to purchase a GitLab.com plan

List of features

• Service desk (EEP / Silver + Gold) - #2887 (closed)
• Merge requests approvers (EES / Bronze) - #2888 (closed)
• Multiple issue boards (EES / Bronze) - #2899 (closed)
• Issue boards with milestones (EES / Bronze) - #2899 (closed)
• Issue board focus mode (EES / Bronze) - #2899 (closed)
• Rebase merge requests before merge (EES / Bronze) - #2888 (closed)
• Squash and merge (EES / Bronze) - #2918 (closed)
• Use fast-forward merged where possible (EES / Bronze) - #2915 (closed)
• Push rules (EES / Bronze) - #2948 (closed)
• Branch permissions for users (EES / Bronze) - #2948 (closed)
• Set weight of issues (EES / Bronze) - #2946 (closed)
• Group-level Webhooks (EES / Bronze) - #2947 (closed)
• Mirror external repositories (EES / Bronze) - #2948 (closed)
• Burndown charts (EES / Bronze) - #2966 (closed)
• Contribution analytics (EES / Bronze) - #2967 (closed)
• Issue/MR templates (EES / Bronze) - #2977 (closed)
• Global code search (i.e. Elasticsearch) (EES / Bronze) - #2978 (closed)
• Audit events (EES / Bronze) - #2988 (closed)
• Export issues (EES / Bronze) - #2987 (closed)

As per https://gitlab.com/gitlab-org/gitlab-ee/issues/2335 we may need to also split this out into a series of issues