Add search query to events and menu items

[Frewacom]

You need to be able to search among all menu items/events. Currently, in the app, you can only search among the fetched data. Since the data is paginated, you need to make sure to scroll and load all data before you can make a "good" search. What we should do instead is to add a new query to the existing endpoints that allows us to specify a custom search term.

Example endpoints:

GET /events?page=1&number=10&search=custom%20search%20query

should return a paginated collection of events that matches "custom search query" in the name (and/or description?).

The same goes for the menu items:

GET /menus/1/items?page=1&number=10&search=custom%20search%20query