API routes middleware

[Chieze-Franklin]

Implement middleware that converts URL queries to appropriate objects

• [x] Convert queries in the form of a=b to where filters { a: b }
• [x] Convert @populate= queries to Mongoose populate object
• [x] Convert @sort=a:asc,b:desc to sort commands
• [x] Convert @limit=10 to limit commands
• [x] Convert @page=2 to pagination commands (include next and prev in the meta)