[server]fix missing services attribute for empty design

[MUzairS15]

Notes for Reviewers
The Services struct had omitempty tag because of which if the design was empty, it was not being streamed inside the response.

Signed commits

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[MUzairS15]

// @aabidsofi19 @leecalcote

[github-actions]

[leecalcote]

Removal of this also leaves the system vulnerable to a nil primary key inside the design, @MUzairS15

[MUzairS15]

The services key as you said should be ever present, and this PR ensures this happens.
Comparing it with primary constraint not null, if design is empty, it is not that services will be null but an empty object.

skipping/removing the key for empty design makes it difficult to understand whether design is actually empty or have got corrupted.

[leecalcote]

The services key as you said should be ever present, and this PR ensures this happens. Comparing it with primary constraint not null, if design is empty, it is not that services will be null but an empty object.

Aha! Ok, that’s very good.