After looking for some extension to cope with many open tabs within Opera, I finally found Josh Perry’s TabManager for Chrome. While it allowed to search in the title text of the tabs for specific words, it did move the found tab to a new window and did do a full string search.
However, I think it would be more useful if the found tab is focused instead of moved to a new window, I changed the behavior. In addition, I changed the search behavior to search for all words within the substrings of the tab title. I now decided to fork the original repository and commit my changes, so that maybe other people can benefit from it or improve it further.
You can find the TabManager at my fork of the original repository.