Create admin dashboard page for viewing transactions

[GabrielMajeri]

For traceability and auditing purposes it's essential for admins to be able to see the list of all transactions (in their various states). We could add a page /admin/transactions for this purpose.

The page should use something like TanStack Query to fetch and cache data and TanStack Table to display it in a tabular format. It is mandatory that for this list to be paginated, since we expect to have hundreds of thousands of transactions in the database eventually.

The data table could have the following columns:

• ID
• Transaction ID (EuPlătesc ID / epid) — possibly shortened to not clutter up the list
• Transaction status (initiated/succeeded/failed)
• Description (the remarks field from the corresponding tax value; this will indicate what tax the user paid)
• Value (in RON)
• First name and last name of payer
• Personal ID code of payer
• Creation timestamp
• Modification timestamp
• Actions (view details)

On the transaction details page (could have a route like /admin/transactions/<transaction ID>) we will also display all of the other details of the transaction: billing info fields (country, city, address, phone number, e-mail).

It would be great if we could also implement a search/filter feature, at least for the name and personal ID code columns.