CLOUDP-237245: Add example for retrying requests

[wtrocki]

Description

Adding example that would support
Tested manually by using API mocks (thanks to @lantoli) for different network issues and status codes.
All works end to end.

Testing

go run ./examples/retry/retry.go      
2024/03/26 20:43:41 [DEBUG] GET https://cloud-dev.mongodb.com/api/atlas/v2/groups?includeCount=true&itemsPerPage=1&pageNum=1
2024/03/26 20:43:41 [DEBUG] GET https://cloud-dev.mongodb.com/api/atlas/v2/groups?includeCount=true&itemsPerPage=1&pageNum=1
2024/03/26 20:43:41 [DEBUG] GET https://cloud-dev.mongodb.com/api/atlas/v2/groups?includeCount=true&itemsPerPage=1&pageNum=1
2024/03/26 20:43:42 [DEBUG] GET https://cloud-dev.mongodb.com/api/atlas/v2/groups?includeCount=true&itemsPerPage=1&pageNum=1

[wtrocki]

12f3972 was added to not got pinged on dependabot updates for examples. No strong opinion if we want that and we can easily remove this commit if needed.

[wtrocki]

@gssbzn Based on your feedback we have:

• Added multi mod support in to the repository
• Moved example specific dependencies to example project
• Extended this PR scope to update golang version of repository
• Updated and reviewed golang CI lint version and configuration.

Let me know if I miss anything

[gssbzn]

is testify still needed here, could we go mod tidy?

[wtrocki]

We do:

"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/mock"

[wtrocki]

I would prefer if we do OpenAPI generator update in the follow up PR as this might involve +60 different file changes.

[gssbzn]

LGTM

[lantoli]

@wtrocki @gssbzn note that for instance cluster creation can throw 500 but still created the cluster so next call will be DUPLICATE_CLUSTER_NAME 400 that will be a bit confusing for clients.
retries are mostly useful when operations are atomic (happen completely or don't happen at all)

[gssbzn]

yes, personally blindly retrying on the Atlas API is not safe and a bad idea