Add `/api` routes that return data in JSON format

Created by: noClaps

Adds /api/communities that returns an object with the following type:

type Response = {
    communities: {
        id: string;
        name: string;
        about: string | null;
        noMembers: number;
        lastActivityAt: string; // time
        createdAt: string; // time
        proPic: {
            url: string;
        } | null
    }[]
}

Adds /api/search that takes q and sort query parameters. If q is missing, error 400 is returned. If no results are found, error 404 is returned. Otherwise, an object with the following type is returned:

type Response = {
    results: {
        id: string;
        name: string;
        about: string | null;
        noMembers: number;
        lastActivityAt: string; // time
        createdAt: string; // time
        proPic: {
            url: string;
        } | null
    }[]
}

where the results object contains the search results, sorted by relevance by default. The available options for sorting are:

• relevance: the default sort if no sort value is provided
• name-ascending: sort by name (A-Z)
• name-descending: sort by name (Z-A)
• activity-ascending sort by activity (oldest to newest)
• activity-descending sort by activity (newest to oldest)
• created-ascending sort by creation date (oldest to newest)
• created-descending sort by creation date (newest to oldest)