Subscription key improvements

[malincrist]

This PR introduces some improvements for the Subscription Key flows in the test console:

1. If the subscription key is required, the header is always present in the "headers" section, and marked as required:
   

2. The "Subscription key" from Authorization section is masked out by default an it can be un-masked:
   

3. If the user tries to send the request without any value completed for the subscription key header, the request will not be sent and an error will be shown: (related issue Incorrect message for invalid/missing subscription key using policy fragment with cors & Users shouldn't be able to send requests when not subscribed. #2202)
   

Similar behavior for GraphQL and WebSocket and subscription key parameter.

[github-actions]

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[arbs-io]

Hi @f-alizada, @malincrist
Has this change introduced a bug? We've noticed over the weekend that the subscription key is now always required. Even if both Product and API have subscription-required disabled.

[malincrist]

Hello @arbs-io , yes, there is a regression in the new release that always marks the subscription key header as required. We have fixed it (see #2382) and will prioritize the deployment of the fix for the affected services. Apologies for the inconveniences created.