Revert new ordering of same day transactions

[tquellenberg]

Describe the bug
#1874 changed the ordering of same day transaction. Before this change transaction were sorted by date, amount and type. The new sorting uses date and updatedAt.
For #1874 there is a second better solution (optional automatic time in addition to date) so that the sorting can be reverted without difficulties.

Two problems arise with the new sorting:

• Imports of same day transactions leads to consistency problems when sell transaction are ordered before buy transactions.
• Every change of a transaction modifies the updateAt and results in an annoying reordering of the transaction list.