webui: new item filter

[or2e]

1. Added "Show only new items" filter The item is considered new if it was added not earlier than 30 days Value is changed in item-service, I did not move it in constants.json

   Screenshot

   

2. Changed the dropdown behavior of additional filters. Now it closes after selecting Also made the open button more visible

   Demo

   https://github.com/verdie-g/crpg/assets/33551334/7864aed4-54fb-4f8e-ab05-072a739c5af2
3. Fixed auto-tests related to search service and indexer