Endpoint enhancements

[chubei]

• [ ] Use GET /$endpoint/record/$key instead of GET /$endpoint/$key
• [ ] Switch /oapi endpoint to a GET method
• [ ] Support GET /count and GET /query
• [x] create a new route to download proto file for typed service. (including types.proto)
• [x] create a route for common proto
• [x] Create a default route for the / endpoint with a simple json response saying (status: 200, message: Dozer APIs v0.1.1) or something.

[aazam-gh]

Hi, can I work on this :)