Implement QueryBuilder

[bsoe003]

The purpose of QueryBuilder class is to convert URI/URL query key-values to Camo-acceptable options. Here's an example:

1. send GET request to the endpoint: /companies?match=name>goo&show=name,location,logo
2. the req value grabbed by express will convert the query to:

   {
       match: 'name>goo',
       show: 'name,location,logo',
   }

3. With QueryBuilder's conversion, we should be able to do following Camo statement:

   const result = await Company.find({ name: 'goo' }, { populate: ['name', 'location', 'logo'] });

Tasks:

• [ ] Create a separate QueryBuilder class with its constructor taking an object as a parameter
• [ ] Create a "private" translator function that will convert URL query properties to Camo-acceptable properties
• [ ] Create a "private" parser function that will parse URL query values to Camo-acceptable values
• [ ] Create a getter instance function for query (e.g. { name: 'goo' })
• [ ] Create a getter instance function for options (e.g. { populate: ['name', 'location', 'logo'] })
• [ ] Create a unit test for QueryBuilder (ensure it covers at least 80% of QueryBulider class)
• [ ] Manually test e2e flow to make sure QueryBuilder is working correctly

Query Specs: TBD

Reference:

• https://docs.mongodb.com/manual/reference/operator/query/