RA-1926: Merge Visits: Remove visitId from URL to prevent NPE if that visit was merged (#410)
* RA-1926 Remove visitId from URL to prevent NPE if that visit was merged
* RA-1926 Remove visit ID if that visit was merged
* RA-1926 Add new method to remove URL visits if necessary
* RA-1926 Add new test file, and 2 new tests, to remove url if that visit id was merged
* RA-1926 Change MergeVisitsPageControllerTest.java file to correct package