Email Verification added

[bicycleman15]

Description

Email verification now added to the backend. User now can't directly login. He/She will have to verify the account first before logging in.

Fixes #142

Type of Change:

Code/Quality Assurance Only

• This change requires a documentation update (software upgrade on readme file)
• New feature (non-breaking change which adds functionality)

Checklist:

Delete irrelevant options.

• [x] My PR follows the style guidelines of this project
• [x] I have performed a self-review of my own code or materials
• [x] I have commented my code or provided relevant documentation, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation

[YashMeh]

@bicycleman15 resolve the conflicts and add comments to your code, also make the necessary changes in the frontend(react-app) .