feat(relocation): Add promo code linking for retries

[hubertdeng123]

Should go in before https://github.com/getsentry/getsentry/pull/13707

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 79.72%. Comparing base (67334be) to head (e553ad5). Report is 9 commits behind head on master.

:exclamation: Current head e553ad5 differs from pull request most recent head 12f9e2f. Consider uploading reports for the commit 12f9e2f to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #69274 +/- ## =========================================== + Coverage 58.20% 79.72% +21.52% =========================================== Files 6430 6435 +5 Lines 285917 286135 +218 Branches 49295 49319 +24 =========================================== + Hits 166415 228122 +61707 + Misses 119061 57576 -61485 + Partials 441 437 -4 ``` | [Files](https://app.codecov.io/gh/getsentry/sentry/pull/69274?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=getsentry) | Coverage Δ | | |---|---|---| | [src/sentry/api/endpoints/relocations/retry.py](https://app.codecov.io/gh/getsentry/sentry/pull/69274?src=pr&el=tree&filepath=src%2Fsentry%2Fapi%2Fendpoints%2Frelocations%2Fretry.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=getsentry#diff-c3JjL3NlbnRyeS9hcGkvZW5kcG9pbnRzL3JlbG9jYXRpb25zL3JldHJ5LnB5) | `85.48% <100.00%> (+33.81%)` | :arrow_up: | ... and [1936 files with indirect coverage changes](https://app.codecov.io/gh/getsentry/sentry/pull/69274/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=getsentry)