Replicate official SDK to fetch results from Temporal

[abhishekjain16]

While running long workflows that require synchronous results, await_workflow_result throws the following exception:

await_workflow_result': undefined method 'type' for nil:NilClass (NoMethodError)

pointing to line https://github.com/coinbase/temporal-ruby/blob/master/lib/temporal/client.rb#L251

Reason:
When trying to fetch workflow execution history with event_type: :close, Temporal sends empty events payload after next event (not necessarily close event)
Calling .first.type fails on empty event.

Fix:
Follow what official SDK does in Go and TS. Create a loop and try and fetch close event till it can find one
TS Example:
https://github.com/temporalio/sdk-typescript/blob/913e67e6381c421c3ed02ee24518adfa1243c84c/packages/client/src/workflow-client.ts#L630

Go Example:
https://github.com/temporalio/sdk-go/blob/626785769094562b39662d6076304c807b596ed9/internal/internal_workflow_client.go#L433-L436

This PR tries to replicate the same behavior

[morgan121]

@bdchauvette We are also getting this error now, is it possible to merge this fix? It's causing us a bit of headache

[abhishekjain16]

@cj-cb @DeRauk Do you think we can merge this? I can fix conflict but only if there is a need to do it