`Domain\Suggestions` command fails when search term contains a trailing `.`

When users search for a domain name with a trailing `.` (e.g. `something.blog.`), the `Domain\Suggestions` command fails with the following error message:
>Could not get TLD of domain suggestion

This is probably an edge case, but there's a chance that a search may contain a typo. While we can strip out the trailing `.` client side, but ideally, the DSAPI should still proceed with the search in such cases, instead of erroring out.

Locate the Domain\Suggestions command and the code path that produces “Could not get TLD of domain suggestion.” Reproduce the failure with `something.blog.`, then add or update coverage for the trailing-dot case; done means the search proceeds without that error.

Written by the indexing model from the issue text.