Set empty props as objects in WPCOM Proxy responses

[puntope]

Changes proposed in this Pull Request:

Context: p1723540799285679/1722414955.111429-slack-C02BB3F30TG

In this PR we convert empty array properties into empty objects.

Screenshots:

Detailed test instructions:

1. Hardcode an empty prop like $data['test'] = []; in the first line of the new prepare_data() function to simulate we get an empty array in a prop.
2. See the prop is returned as {}
3. Rest of the props still working as before.

Additional details:

Changelog entry

Fix - Return empty array props as empty objects in WCOM Proxy responses

[codecov]

Codecov Report

Attention: Patch coverage is 92.85714% with 1 line in your changes missing coverage. Please review.

Project coverage is 65.0%. Comparing base (5ddcd31) to head (42281ed).
Report is 64 commits behind head on develop.

Files	Patch %	Lines
src/Integration/WPCOMProxy.php	92.9%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             develop   #2519      +/-   ##
============================================
+ Coverage       63.8%   65.0%    +1.3%     
- Complexity         0    4585    +4585     
============================================
  Files            323     475     +152     
  Lines           5052   17898   +12846     
  Branches        1222       0    -1222     
============================================
+ Hits            3222   11640    +8418     
- Misses          1664    6258    +4594     
+ Partials         166       0     -166     

Flag	Coverage Δ
js-unit-tests	?
php-unit-tests	65.0% <92.9%> (?)

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Files	Coverage Δ
src/Integration/WPCOMProxy.php	74.1% <92.9%> (ø)

... and 797 files with indirect coverage changes

[jorgemd24]

Thanks @puntope for working on this. I left a comment about calling get_data and set_data without checking the $response type.

[jorgemd24]

The $response can be one of these types: WP_REST_Response, WP_HTTP_Response, WP_Error, or mixed. If $response isn't a WP_REST_Response, it will throw an error because get_data or set_data might no be defined.

[puntope]

Thx @jorgemd24 I updated the code so now it returns early if the response is not WP_REST_Response. Can you take another look?

[jorgemd24]

Thanks @puntope for the adjustment. LGTM 👍