feat(account, transaction): reconciliation and transaction list

[fres-sudo]

This PR aims to add the possibility to change the total amount of your bank account.

Steps to take a reconciliation:

• Go to Settings Page
• Go to Accounts
• Just change the total amount and click "Update Balance"

By doing those steps, the total amount of your accounts updated and a new transaction "Reconciliation" is being created.

This PR also improve the transaction_list.dart code by using ListView.separatedand ListTile to stick to material widget.

-Closes #197

[theperu]

Great job! I had a brief look at your changes and it's working well. I would add this feature also in account_page.dart for the UI you could do something similar to these screenshots. After this I would also add a Your transactions text before the transaction list to divide more the sections.

Feel free to change the text or how it looks, it's here just to give you an idea 😁

Before tap

After tap

[mikev-cw]

Hello, and thank you for this contribution!! I see that overall the process is working very well!
Just noticed something about the number formatting. Tested only on Android, started from 0 and filled DB with demo data.

When i tap the account, i see the current balance with a lot of decimal digits:

Also the reconciliation transaction is created with the same problem on the DB:

I think that's just the limitation of the binary representation of floating point numbers. Can you check on that? Thank you! Other than that i think that your PR is ready for the next steps!