Referral emails tracking

[kkartunov]

1. Add tracking for refer emails sent from gig details page.
2. Error flows to implement:

• not allowed to send to yourself
• already referred
• already sent to that email

[SathyaJayabal]

Case 1: User referred another user successfully

Error Scenarios:
Case 2: User tries to refer them self

Case 3: User tries to refer user who is already placed

Case 4: User tries to refer user who they already referred

[SathyaJayabal]

verified on staging:

1. succesful referral:


error scenarios:
2. not allowed to send to yourself

3. already referred

4. already sent to that email

[SathyaJayabal]

verified on prod