[INTERNAL] sap.m.Tree: enhance the documentation of functions
[INTERNAL] sap.m.Tree: enhance the documentation of functions

- expandToLevel
- collapseAll

Change-Id: I8c13239e1ef5ce91ea5a1d3ac491afea0402a646
BCP: 1770181024

SAP/openui5,cschuff/openui5,olirogers/openui5,SQCLabs/openui5,SAP/openui5,cschuff/openui5,SAP/openui5,SAP/openui5,nzamani/openui5,SQCLabs/openui5,nzamani/openui5,cschuff/openui5,olirogers/openui5,olirogers/openui5,SQCLabs/openui5,nzamani/openui5