Payment and IAM update

What's Changed

• feat: Google auth, multi-coldkey linking, and SMTP by @kingcharlezz in #48
• Feat/tmc pay integration by @rob-dendrite in #52
• Bring back two credit package deals, and actually grant the bonus by @rob-dendrite in #53
• Match the TMC PAY client to the live merchant API by @rob-dendrite in #54
• Seed TMC PAY quotes from TMC PAY's own rate endpoint by @rob-dendrite in #55
• Feat/tmc pay multi currency payments by @rob-dendrite in #57
• Serve the payment currencies without a session by @rob-dendrite in #58
• Feat/tmc pay multi currency payments by @rob-dendrite in #59
• Report the payment redirect targets on the purchase response by @rob-dendrite in #60
• Fix/tmc pay webhook signature by @rob-dendrite in #61

Full Changelog: v1.0.1...v1.0.2