Mm 47422 signup token (#21662)

* When service setting flag is on, self hosted workspaces can initiate process for self-serve sign up
* Add hosted_customer api.

einterfaces/cloud.go

@@ -32,6 +32,7 @@ type CloudInterface interface {
 	GetLicenseRenewalStatus(userID, token string) error
 	InvalidateCaches() error
 
+	BootstrapSelfHostedSignup(req model.BootstrapSelfHostedSignupRequest) (*model.BootstrapSelfHostedSignupResponse, error)
 	CreateOrUpdateSubscriptionHistoryEvent(userID string, userCount int) (*model.SubscriptionHistory, error)
 	HandleLicenseChange() error
 }