fix(tree): not allowing horizontal overflow (#18215)
fix(tree): not allowing horizontal overflow (#18215)

The way the tree styles were set up initially means that the tree element can't cause its parent to overflow. Given that the tree can have a lot of nesting, this is bound to happen with deeper trees. These changes remove the default `overflow: hidden` since it doesn't seem to be doing much.

Fixes #18182.
andrewseguin/material2,mmalerba/material2,angular/components,andrewseguin/material2,crisbeto/material2,Jefiozie/material2,Jefiozie/material2,mmalerba/material2,angular/components,angular/components,andrewseguin/material2,josephperrott/material2,Jefiozie/material2,DevVersion/material2,andrewseguin/material2,mmalerba/material2,crisbeto/material2,angular/components,josephperrott/material2,DevVersion/material2,josephperrott/material2,Jefiozie/material2,DevVersion/material2,josephperrott/material2,DevVersion/material2,mmalerba/material2,crisbeto/material2,crisbeto/material2,Jefiozie/material2,DevVersion/material2,mmalerba/material2,andrewseguin/material2,josephperrott/material2