give inline notebook chat its own setting for using v2 controller (#270658)

* make notebook inline v2 usage independent

* try to adjust v1 vs v2 context keys

* fix conditionals, delay cell editor check

* fix v1 context key, editor still not always identified as cell editor

* create alternate inline chat contribs for notebooks

* Revert "create alternate inline chat contribs for notebooks"

This reverts commit f8667269cdc2ca932a85e38ca819a0813ef3ec60.

* fix helper method, use it to get the notebook Editor

* override new method for test

* unused import