A traceback occurs when the user changes the exchange rates in the `account_multicurrency_revaluation_report`.

To reproduce this issue:
1) Activate multi-currency from `Accounting/Configuration/Currencies` 
2) Open `Unrealized Currency Gains/Losses` report
3) Change the rate exchanges by giving any `special-characters/letters`

Error:-
```
ValueError: could not convert string to float: '0,0025thsg'
```

This is because initially, the input type for exchange rates was number.
However, due to major improvements from this commit, it was changed to text.

https://github.com/odoo/enterprise/pull/55012/commits/0f8de4c15656b151a83c869dd81d1d62aab52f70

Indeed, the user can give any letter or special character when the input type is text.
This leads to traceback at multiple lines

https://github.com/odoo/enterprise/blob/861a071f655a9d46ce8bf502575e9e2303fc1174/account_reports/models/account_multicurrency_revaluation_report.py#L54

The currency exchange rates should be numbers. 
So changing the input type to number can resolve this issue.

sentry-5770342702