Add search api endpoints for each resource

[dreamingblackcat]

Now that we have normal CRUD functionality for individual admin pages.

We need a basic name based search endpoint for each of the following admin pages:

• Users
• Students
• Schools
• Donations

The url should be GET /<resource name>/search?q=yoursearchtermhere.

For users, it should search try to search the term in both username and display_name.
For students, it should search by name.
For schools, it should search by name.
For donations, it should search by donator's username and display_name as well as student's name.

[khinezarthwe]

Currently we have the following endpoint, we will update the donations soon.

• https://app.thingaha.org/api/v1/users/search?query=မခိုင်
• https://app.thingaha.org/api/v1/students/search?query=မခိုင်
• https://app.thingaha.org/api/v1/schools/search?query=ကျောင်းကြီး