ModuleSearchBase has wrong modified date

## Describe the bug
All items have the modified date of the last indexing operation.

## Expected behavior
Modified date should be the date of the last change of the item.

## Additional context
Querying the newest items from the search base returns always a lot of FAQ items on the top, and the "real" newest items are listed much more "down the list".

The problem is obviously line 360 in the business controller class:

ModifiedTimeUtc = DateTime.Now.ToUniversalTime()

This should be the modified date/time of the FAQ item.

Start at line 360 in the business controller class, where ModuleSearchBase assigns ModifiedTimeUtc, and inspect the FAQ item data available there. Trace the item's actual modification timestamp and verify that newest-item queries use it rather than the indexing time.

Written by the indexing model from the issue text.