Collect errors from automatic suggestion backends

### Describe the problem

Currently, automatic suggestion backends silent themselves for errors which are most likely caused by rate limiting:

https://github.com/WeblateOrg/weblate/blob/8b514cb50db9a4839c0e48350d4d5c5c3fe13250/weblate/machinery/base.py#L246-L259

This is nice for user viewed suggestions as it doesn't show an error message on each page.

But this makes such errors invisible to admins.

### Describe the solution you'd like

Collect such errors and display them in the management interface.

### Describe alternatives you've considered

_No response_

### Screenshots

_No response_

### Additional context

_No response_