feat: implementation of paid route for event invoices

[shreyanshdwivedi]

Fixes #3349

Short description of what this resolves:

As soon as the event invoice payment has been authorized & becomes successful, the user must be redirected to the route where he can view the paid payment for the invoice.

Changes proposed in this pull request:

• Adds /paid route for event invoice

Checklist

• I have read the Contribution & Best practices Guide.
• My branch is up-to-date with the Upstream development branch.
• The acceptance, integration, unit tests and linter pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

[kushthedude]

@shreyanshdwivedi Have a look at them

[shreyanshdwivedi]

@CosmicCoder96 made the changes. Please have a look

[shreyanshdwivedi]

@CosmicCoder96 please review

[shreyanshdwivedi]

@kushthedude @uds5501 @mrsaicharan1 please review

[mrsaicharan1]

LGTM

[shreyanshdwivedi]

@kushthedude @CosmicCoder96 please review

[shreyanshdwivedi]

@CosmicCoder96 please have a look. We cannot merge it even after 3 approvals