Fix: https://github.com/rails/rails/issues/43472

The reporter is held by the executor, but the `Rails` module provides a
nicer `Rails.error` shortcut.

For ease of use, two block based specialized methods are exposed.

`handle`, which swallow errors and forward them to the subscribers:

```ruby
Rails.error.handle do
  1 + '1' # raises TypeError
end
1 + 1 # This will be executed
```

`record`, which forward the errors to the subscribes but let it
continue rewinding the call stack:

```ruby
Rails.error.record do
  1 + '1' # raises TypeError
end
1 + 1 # This won't be executed.
```

For cases where the blocked based API isn't suitable, the lower level
`report` method can be used:

```ruby
Rails.error.report(error, handled: true / false)
```