Promote Issue weight

Related to https://gitlab.com/gitlab-org/gitlab-ee/issues/2624

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Design

Promote trial or license activation for regular EE on-prem sites.

Admin

• Having Start GitLab EE trial button.
• Read more

• Link to the document, so users can know more about the feature.
• Link: https://docs.gitlab.com/ee/workflow/issue_weight.html

• Copy:

Improve issues management with Issue weight and GitLab Enterprise Edition. [Read more]

Non-admin

• Copy:

Contact your Administrator to improve issues management with Issue weight and GitLab Enterprise Edition. [Read more]

Admin	Non-admin

For GitLab.com the feature promotion needs to go to purchase a GitLab.com plan

Admin

• Having Upgrade to GitLab EE button.
• Copy:

Upgrade your plan to activate Issue weight. [Read more]

Non-admin

• Copy:

Contact your Administrator to upgrade your plan to activate Issue weight. [Read more] 

Admin	Non-admin