Simply switch branch before executing mvn failsafe:integration-test
. This is common pattern.
Maven Failsafe Plugin has no support for switching branches and no support for Version control systems (VCS) - and this is good, because this other plugin responsiblity.
This is easy to switch branch in tools like Jenkins. Create one job per branch, changes to code in branch should trigger jenkins build. Jenkis has support for private maven repositories, this will help with artifact collision. Also is possible to share workspace (results) from first job with second job.
In your case build job pipeline in jenkins, after first job from master execute job from branch to verify integration tests.