[CLD-9186] Remove onboarding tasklist, add preview banner (#31203)

* Remove pricing modal. Adjust everywhere to instead open mattermost.com/pricing. When air gapped, don't show buttons to view plans.

* Fix lint

* Further clean up of unused code. Fixes for linter

* Remove onboarding tasklist for previews, add Cloud previer banner

* Fixes for linter, i18n

* Revert dev lines

* Fix lint

* When below one minute, switch to seconds

* fix linter

* fixes for PR feedback

* useExternalLink for opening pricing modal with enriched params

* Fix i17n

* Fix style, tests

* Update webapp/channels/src/components/announcement_bar/cloud_preview_announcement_bar/index.tsx

Co-authored-by: Guillermo Vayá <guillermo.vaya@mattermost.com>

* Fix linter

---------

Co-authored-by: Guillermo Vayá <guillermo.vaya@mattermost.com>

server/public/model/cloud.go

@@ -191,6 +191,7 @@ type Subscription struct {
 	CancelAt                *int64   `json:"cancel_at"`
 	WillRenew               string   `json:"will_renew"`
 	SimulatedCurrentTimeMs  *int64   `json:"simulated_current_time_ms"`
+	IsCloudPreview          bool     `json:"is_cloud_preview"`
 }
 
 func (s *Subscription) DaysToExpiration() int64 {

server/public/model/license.go

@@ -350,6 +350,11 @@ func (l *License) IsStarted() bool {
 	return l.StartsAt < GetMillis()
 }
 
+// Cloud preview is a cloud license, that is also a trial, and the difference between the start and end date is exactly 1 hour.
+func (l *License) IsCloudPreview() bool {
+	return l.IsCloud() && l.IsTrialLicense() && l.ExpiresAt-l.StartsAt == 1*time.Hour.Milliseconds()
+}
+
 func (l *License) IsCloud() bool {
 	return l != nil && l.Features != nil && l.Features.Cloud != nil && *l.Features.Cloud
 }