Migrate `gamer-activity.js` to echo-base

[Jaden51]

Description

The goal of this issue is to migrate the gamer-activity.js endpoints over to echo-base. This issue takes the current implementation of the gamer-activity route in Express.js and writes the code in Go. The functionality should mostly stay the same but making improvements to the original implementation.

Requirements

• Complete functionality of the current implementation
• Write tests