Digestion with Exp3I at a circular sequence beginning/end

This problem was found during solving of the UGENE-6232 issue.

Get a sequence from the above-mentioned issue and find a "Esp3I" restriction site.

If you open REBASE info about this site, you will see, that this site has a 4-chars overhang. In case of the current sequence, the overhang has only 2 chars from the beginning of the sequence and the first sticky end at the 0-position. But, 2 more chars for this overhang should be highlighted from the end of sequence and the above-mentioned sticky end should be at the 'sequenceLength - 2' position.

In case of non-circular view, the behavior shouldn't be changed. Notice, that any sequence can be declared as circular or not in the project tree view, so, in case of changing of this option, restriction sites should be reculculated.