Warnings about the contents of some Functions.

[Ibrahim-Halil-Kuray]

Subject of the issue

In some functions, return is not read due to logical error(s).

• • main>handlers>blockchain>payment_listener.go
  • main>handlers>blockchain>signature_listener.go
  • 
• • main>handlers>payment>handlers_test.go
  • 
• • main>handlers>template_ide.go
  • 
• • service>workflow.go
  • 
• • sotorage>database>db>mongo.go
  • 
  •