fireapp-3.119.0-alpha.7765
Chim/feature/add notification service (#305)
## Describe your changes
I've add 3 functions:
1. `send_notification` in the `NotificationService` class
2. `get_fcm_token` and `notify_user` in the `FCMTokenRepository` class
Functionalities:
1. Given a list of fcm token, `send_notification` will allow other parts
of the program to call for sending any message or notification.
2. Given a user id, `get_fcm_token` will retrieve all fcm tokens for a
given user and return in a list of token string.
3. Gvien a userId or a list of fcm token, `send_notification` can be
used to send notification to users.
## Issue ticket number and link
[Jira](https://fireapp-emergiq-2024.atlassian.net/jira/software/projects/FIR/boards/2?selectedIssue=FIR-99)