Antelope : Creation Flat Nodes

[zolting]

Added the Creation Flat Nodess table for Antelope. The README and commented out code indicated that creation_trees was to be implemented, but that would have been hard considering that array support is not there yet.

[DenisCarriere]

1. renamed TABLE to creation_tree

Since that is the first child data of transactions.creation_tree
In EOSQ, the term creation_tree is already defined instead of flat nodes https://eos.eosq.eosnation.io/tx/fff5b4ee04f724313f33007ee4244427699b96f9531a56838d0d72e661883a40

2. remove `block_date` from PRIMARY KEY ```sql PRIMARY KEY (tx_hash, creator_action_index, execution_action_index) ORDER BY (tx_hash, creator_action_index, execution_action_index) ```