cubicweb #3259691 Undo action: performances on delete [validation pending]

In case there are a lot of data stored in undo related tables, the deletion of tx_entity_action and, particulary, tx_relation_actions tables takes a really long temps because of lack of indexes.

The following indexes can be usefull to add

# create a btree index on tx_time
CREATE UNIQUE INDEX tx_time_id ON transactions (tx_time);
# create simple indexes
CREATE INDEX tx_ent_uuid_id ON tx_entity_actions (tx_uuid);
CREATE INDEX tx_rel_uuid_id ON tx_relation_actions (tx_uuid);
done in3.17.11
load left0.000
closed by#722635e530a0 [server] Add missing indices for undo support (closes #3259691)
patch[server] Add missing indices for undo support (closes #3259691) [applied]