[Balance Sheet] Download attached file naming schemes

The user has to be able to download an .zip archive containing either all the information in the view balance sheet section or a selection of balance sheet entries.

**For example:**
If I already inputted the month of may (income and expenses) and already processed all the work I had to on this interval, i can filter all the balance sheets entry to show just May entries and click **_Download_** and and archive containing:

- an excel table with all entries with all information on each balance sheet line,
- all the uploaded documents for this selection.

It is not relevant how each of the supporting documents is named, it is relevant that the whole archive is named following this scheme: **_Year/Month/StartDate-EndDate_Moneda_Raport_IBAN_**.

- (Ex: 2021/05/01-31_RON_Raport_RO06BTRL0000090000876756 or 2021/10/07-24_RON_Raport_RO06BTRL0000090000876756 etc)

**_*(Nice to have)_** If the supporting documents can be named after a specific scheme then, it should be **_Year/Month/Date_DocumentName_Amount_Currency_** where:

- Year/Month/Date is the value added in the Balance sheet not the date when you added the document in the platform.

**Example**: If I added an expense in July on the 5th my Balance sheet line will say:
_Abonament mailchimp / 05/07/2021 / 123 / Cheltuiala / Cheltuieli Directe - Abonamente_
Then the name of the document will be _2021/07/05_Abonament Mailchimp_123_RON_