Amathur/table tree api with cache

This is a new approach to the table tree api:

Added a helper class: CreateTableTreeDataHelper

This will create items for the user and also retain a cache of the keys, so that we can make changes really fast.

Again this is a pattern approach instead of something consumer needs to do.

Request review : I really want to ship this before I leave for holiday on Friday.

I am updating the docs in background please let me know what you think of the code until then