Clean up integrationrequest thrift message structure

Cleanup IntegrationRequest structure and UI, it has many repeated fields.

• repositoryState, could be used to store source_ref
• productName and productVersion should be replace by product repositoryState
• productRef can go away
• repositoryState could be merge into modules
• type is useless if we have reviewAction
• testedChanges, destination_branch are used only with some reviewAction so maybe it would ok to change reviewAction to be a struct

UI could be altered to ask for 2 repository states (module and product) and target branch. The product part can be pre-filled with more or less correct values