Add search feature in layouts screen

[jatinkatyal13]

Currently, the layouts page displays the api data directly but there is no option to search the layouts

ToDos

Frontend

• Add Text Input on top of layout list in frontend/pages/layouts/index.js with onChange method that fires a search action
• Update loadLayouts action to take another query parameter q with default value being an empty string.
• After receiving search data unload all store data, so that only filtered data is displayed. Add a unloadAll flag in the action and replace the state rather than adding in the reducers based on this flag to avoid jank.

Backend

• In src/services/layouts/handlers.js accept q in query params that searches the given query in layout titles. Also, add the q in schema