[Maintenance] Use of Proper Return Statements

[TanmoySG]

Use proper return statements and methods instead of using random messages.

[Checkpoints]

• [x] Remove existing un-standardized return statements
• [x] Return proper and standard statements
• [x] Use standardized return codes wherever applicable
• [x] Implement #40 when neccessary

[Snippets]

Change these

 # in requestHandler.py
return "Incorrect OTP", {}

if verification_mail not in authlib.keys():
    return "Return something" # Change Later

[Additional Information]

Track where changes are required. (Add snippet if applicable)

• [x] requestHandler.py

  if verification_mail not in authlib.keys():
  return "Return something" # Change Later

• [x] Add as neccessary