MM-44509 - subscription change not reflected after trial (#20352)

* MM-44509 - subscription change not reflected after trial

* fix the tests

* receive the subscription id as param, defer the cache invalidation

* validate business email with body request

* update api request to accept json body payload

* fix unit tests

* fix tests after merge conflict fixes

Co-authored-by: Pablo Velez Vidal <pablo.velez@mattermost.com>
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

model/cloud.go

@@ -84,6 +84,11 @@ type CloudCustomer struct {
 	PaymentMethod  *PaymentMethod `json:"payment_method"`
 }
 
+type StartCloudTrialRequest struct {
+	Email          string `json:"email"`
+	SubscriptionID string `json:"subscription_id"`
+}
+
 type ValidateBusinessEmailRequest struct {
 	Email string `json:"email"`
 }