[#64263] Add trial enterprise banner

[mrmir]

Ticket

https://community.openproject.org/work_packages/64263

Notes

• Most enterprise banners worked out of the box, as they are always called in their respective views and the banner component itself decides if it is rendered or not based on the token
• Some cases needed additional changes, since their old implementations had additional checks to display either the banner or the feature, and both need to be possible simultaneously for this feature
• As this depends on the way the trial token is accessed/checked, some checks may be redundant. I don't know if something like EnterpriseToken.allows_to?(:work_package_sharing) || EnterpriseToken.trialling?(:work_package_sharing) will make sense after the work for multiple tokens is done

Open points

• With regards to the thread Oliver started in Element about frontend logic, I'm not sure what we should do as that commit he mentioned is a part of this PR. Since we're unsure of the direction to take and he's away for a while still, I would propose to either keep this open until he's back or merge it in and then create a code maintenance WP to take a look at it again and decide if we want to remove the frontend checks entirely over there. Thoughts?

Works for

• baseline_comparison: Baseline Comparisons
• board_view: Advanced Boards
• conditional_highlighting: Conditional Highlighting
• internal_comments: Internal Comments
• custom_actions: Custom Actions => Fullscreen
• custom_field_hierarchies: Custom fields of type hierarchy
• customize_life_cycle: Customize Life Cycle
• date_alerts: Date Alerts
• define_custom_style: Custom theme and logo => Fullscreen
• edit_attribute_groups: Edit Attribute Groups
• gantt_pdf_export: Gantt PDF Export => No banner
• ldap_groups: LDAP users and group sync => Fullscreen
• nextcloud_sso: Single Sign-On for Nextcloud Storage
• one_drive_sharepoint_file_storage: OneDrive/SharePoint File Storage => Fullscreen
• placeholder_users: Placeholder Users => Fullscreen
• project_list_sharing: Project List Sharing
• readonly_work_packages: Readonly Work Packages
• sso_auth_providers: Single sign-on
• team_planner_view: Team Planner View => Fullscreen
• virus_scanning: Antivirus Scanning
• work_package_query_relation_columns: Work Package Query Relation Columns
• work_package_sharing: Share work packages with external users
• work_package_subject_generation: Work Package Subject Generation

Merge checklist

• Added/updated tests
• Added/updated documentation in Lookbook (patterns, previews, etc)
• Tested major browsers (Chrome, Firefox, Edge, ...)

[cbliard]

Nice!

I found some blocking issues:

• (half-)wrong upgrade url for "Buy now" button
• in admin > custom fields, the banner is always visible. It should be visible only when hierarchy type is selected.

Other than that it's merely some code comments.