feat: add volunteer current camp status API

Create a new API to determine the volunteer’s current medical camp status.

The status is based on:

Today’s camp availability

Volunteer registration status

Volunteer attendance status

The API will return a status that the frontend uses to decide the screen:

No camp scheduled screen

Camp registration page

QR code attendance screen

Volunteer dashboard

Reuse the existing signup and attendance logic.

Do not duplicate or modify existing routes or services.

1.creating a new end point for /volunteer/signup-status

2.After volunteer can signup for camp then signup is changed to true

3.After signup admin can mark the attendance for volunteer