[BUG] Results are set to false after successful form submission

**Steps to reproduce:**

1. Dump result arrray in form template
2. Submit form with correct data
3. See dumped result

**Expected result:**

Returned result is filled with information about what happened during form processing. I can use this information as explained in https://github.com/bolt/boltforms/blob/4.1/templates/form/form.twig#L7

**Actual result:**

All results are set to false, so https://github.com/bolt/boltforms/blob/4.1/templates/form/form.twig#L40 this never happens as `result.pass('email')` is always false, even with correct form submission.
Therefore, comment line at https://github.com/bolt/boltforms/blob/4.1/templates/form/form.twig#L7 is not true as result array is always false.

**Caused by:**

Form after submission (with POST) gets redirected to same page (with GET) in `src/Submission/Processor/Redirect.php:90` but this happens before updated Result is returned to user in `src/Submission/Processor.php:163`

Also `feedback.redirect` is not configured in my case.

**What helped:**

Commenting out lines 88-92 in file src/Submission/Processor/Redirect.php worked out for me, but I am sure there is a better solution.

I am not against redirecting after submission, but the result should be kept, for example as flash messages.