[core] /itemsearch support

[sruon]

I affirm:

• I understand that if I do not agree to the following points by completing the checkboxes my PR will be ignored.
• I understand I should leave resolving conversations to the LandSandBoat team so that reviewers won't miss what was said.
• I have read and understood the Contributing Guide and the Code of Conduct.
• I have tested my code and the things my code has changed since the last commit in the PR and will test after any later commits.

What does this pull request do?

Useless these days but it's only a couple of lines and it reuses the translation maps.
All the packet does is send the item ID matching the passed name and the client checks its local containers to display the message.

Steps to test these changes