Avoid using <a> tags in translation strings

[ramiy]

Replace the old string:

<a href="%1$s">%2$s at %3$s</a>

With the new:

%1$s at %2$s

Moving the <a> tag out of the translation string to the code.

[SergeyBiryukov]

In 35665:

I18N: Remove <a> tag from translatable string in wp-admin/comment.php.

Props ramiy.
See #34686.

[SergeyBiryukov]

In 35666:

I18N: Remove <a> tag from translatable string in wp-admin/includes/class-wp-comments-list-table.php.

Props ramiy.
Fixes #34686.