Creating back-end code for reacting with emojis

[aalman3]

In this issue, we will add a feature for reacting to messages in topic discussions with emojis. This issue will focus on the back-end code of the issue. The back-end code will save and store the emoji that was used to react into the database.

Estimated effort:
The task will require about 3-4 days to complete. Bugs and other issues might take another day to fix. Around 5 days in total.

Dependencies among other tasks:
This issue will depend on the front-end code for this feature (Issues #56 #58)

Initial assignments for team members:
Initially assigned to Abdallah Almana: @aalman3.

Milestones to indicate which sprint the issue should be completed in:
Sprint 2.

Acceptance criteria:
dont know how yey