진행중 API 작업 1차 (1.5.0 에 언급된 API 반영)

[riflockle7]

ref: https://www.notion.so/duckie-team/Endpoint-ba3bfc5d7e274d0ab0ba8eda2a5259a8?pvs=4

새로 생성

• GET /exams/funding
• GET /home/funding
• GET /exams/upcoming
• PATCH /problems/:id
• POST /problems
• GET /exams/tags

기존 API 수정

• GET /exams/:id
• POST /exams