[RQ-58] Adding four usage attribution endpoints

[api-clients-generation-pipeline]

See DataDog/datadog-api-spec#481

[jirikuncar]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[codecov]

Codecov Report

Merging #384 into master will decrease coverage by 0.42%.
The diff coverage is 37.27%.

Impacted Files	Coverage Δ	Complexity Δ
...ava/com/datadog/api/v1/client/api/IpRangesApi.java	81.48% <ø> (ø)	3.00 <0.00> (ø)
...adog/api/v1/client/model/EventQueryDefinition.java	46.42% <ø> (ø)	9.00 <0.00> (ø)
...atadog/api/v1/client/model/LogQueryDefinition.java	45.76% <ø> (ø)	16.00 <0.00> (ø)
...ava/com/datadog/api/v1/client/model/UsageSort.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)
...atadog/api/v1/client/model/UsageSortDirection.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)
...og/api/v1/client/model/UsageCustomReportsMeta.java	14.28% <14.28%> (ø)	2.00 <2.00> (?)
...og/api/v1/client/model/UsageCustomReportsPage.java	14.28% <14.28%> (ø)	2.00 <2.00> (?)
.../client/model/UsageSpecifiedCustomReportsMeta.java	14.28% <14.28%> (ø)	2.00 <2.00> (?)
.../client/model/UsageSpecifiedCustomReportsPage.java	14.28% <14.28%> (ø)	2.00 <2.00> (?)
...lient/model/SyntheticsAssertionJSONPathTarget.java	16.66% <16.66%> (ø)	4.00 <4.00> (?)
... and 72 more