Search feature improvements

[tsviz]

Make the search feature more interactive.

### Tasks
- [ ] https://github.com/octodemo/java-springboot-demo/pull/42
- [x] When searching for an item, user should see populated lists of items after they inserted a characters or a group of characters.
- [x] Make sure the search request is being done only after 2-3 seconds so it does become too resourcefull and expensive.
- [x] Make sure the Controller and the model are compatible with the new changes to the search feature improvements