Band tree is not updated if a parent is changed for the band

[m-orlova]

Steps to reproduce:

1. Open the Report browser
2. Click on the Create popup button and select New
3. Add a child band in the Root band (e.g. Band1)
4. Add a child band for the band from the previous step (e.g. Band2)
5. Change a parent for the Band2, select the Root band

AR: The band tree is not updated and Band2 is not shown as a child for the Root band