This includes two parts, first is to change the condition for an organisation to be able to use the bank accounts from organisations from parent groups. This is useful for the case where organisations from subgroups does not represent different legal entities but simply some "business units".
The condition for that have always been: if organisation does not contain bank account, this organisation can use bank accounts from the parent groups.
To be consistent with other places, such a closing accounting periods or setting grouping references, change the condition to: if the organisation does not contain accounting periods, this organisation can use bank accounts from parent organisations.
The behavior should not change much and allow to create bank accounts or cash registers that can be used only in one sub-group organisation.
Second part is about making it visually easier to understand which organisation the bank account belong to by adding some non-selectable options in the select for the organisations. This is only enabled when available bank accounts are not all contained in the same organisation.
