Fetch budget recommendations from the Google Ads API

[mikkamp]

Changes proposed in this Pull Request:

Initial implementation for fetching Budget Recommendations from the Ads API.

It will need some additional testing because regardless of country I'm always getting the same recommendations back, which are much lower than the ones we suggest in the database tables. For example for IE we suggest 10 EUR.

Detailed test instructions:

1. Reinstall composer dependencies rm -rf vendor && composer install
2. Test API request https://domain.test/wp-json/wc/gla/ads/campaigns/budget-recommendation?country_codes[]=IE
3. Observe results:

{
    "currency": "EUR",
    "recommendations": [
        {
            "daily_budget": 2.4,
            "metrics": {
                "cost": 16.8,
                "conversions": 2.8,
                "conversions_value": 111.37227762418706
            },
            "country": "IE"
        }
    ]
}

Additional details:

Project Thread:

Changelog entry

• Add - Fetch budget recommendations from the Google Ads API.

[codecov]

Codecov Report

Attention: Patch coverage is 32.21477% with 101 lines in your changes missing coverage. Please review.

Project coverage is 66.9%. Comparing base (731d028) to head (a575a4b).

Files with missing lines	Patch %	Lines
src/API/Google/BudgetRecommendations.php	0.0%	82 Missing ⚠️
src/API/Google/Query/AdsCountryQuery.php	0.0%	11 Missing ⚠️
...ernal/DependencyManagement/CoreServiceProvider.php	0.0%	4 Missing ⚠️
src/Google/Ads/ServiceClientFactoryTrait.php	0.0%	2 Missing ⚠️
src/Options/TransientsAwareTrait.php	33.3%	2 Missing ⚠️

Additional details and impacted files

@@                        Coverage Diff                         @@
##             feature/budget-recommendations   #2795     +/-   ##
==================================================================
- Coverage                              67.2%   66.9%   -0.3%     
- Complexity                             4676    4699     +23     
==================================================================
  Files                                   480     484      +4     
  Lines                                 19569   19698    +129     
==================================================================
+ Hits                                  13155   13184     +29     
- Misses                                 6414    6514    +100     

Flag	Coverage Δ
php-unit-tests	66.9% <32.2%> (-0.3%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...Controllers/Ads/BudgetRecommendationController.php	100.0% <100.0%> (ø)
...nal/DependencyManagement/GoogleServiceProvider.php	95.0% <100.0%> (+<0.1%)	⬆️
...ernal/DependencyManagement/RESTServiceProvider.php	100.0% <100.0%> (ø)
src/Options/TransientsAwareInterface.php	100.0% <100.0%> (ø)
src/Google/Ads/ServiceClientFactoryTrait.php	0.0% <0.0%> (ø)
src/Options/TransientsAwareTrait.php	33.3% <33.3%> (ø)
...ernal/DependencyManagement/CoreServiceProvider.php	0.0% <0.0%> (ø)
src/API/Google/Query/AdsCountryQuery.php	0.0% <0.0%> (ø)
src/API/Google/BudgetRecommendations.php	0.0% <0.0%> (ø)