Added classes on button click to firestore database

[jaivsh]

Description

I've added the classes on clicking the save button to the firestore database,which was not being added previously. I've also created methods on the recent_alerts screen to fetch all these data documents from firestore to the recent_alerts class..

Fixes #381

Have you read the Contributing Guidelines on Pull Requests?

• [x] Yes
• [ ] No

Type of change

• [x] New feature (non-breaking change which adds functionality)

Checklist:

• [x] My code follows the style guidelines(Clean Code) of this project
• [x] I have performed a self-review of my own code
• [x] My changes generate no new warnings
• [x] I have added tests/screenshots(if any) that prove my fix is effective or that my feature works.

[jaivsh]

@avinashkranjan please see this PR

[jaivsh]

@avinashkranjan resolved conflicts, please merge