Expose information about the build jobs queue to the user

[kwiatekus]

Description

Make users aware of the simultaneous builds limitation.

Acceptance Criteria

• Provide status information in the function CR in case function build waits in queue
• Expose the current value for the limit in the serverless status and in the UI for serverless CR.

Testing strategy
New automated test is expected that covers the following:

• when a default serverless spec is applies, operator should enrich the status with the information of currently used value
• when a user reconfigures spec.functionBuildMaxSimultaneousJobs the operator should update the status information
• when there is no vacancy in the build queue, the information that function waits for a free slot is reflected in the status of the function

Reasons
We are limiting the number of simultaneous builds. (Configurable here). Once a build job waits in queue the user has no information about that which results in bad user experience.

[kyma-bot]

This issue or PR has been automatically marked as stale due to the lack of recent activity.
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[kwiatekus]

Should be implemented only after this POC is finished with negative result

[kwiatekus]

We are planning to get rid of build process in serverless