Add request wrappers to php_fpm

[ChristineTChen]

What does this PR do?

A brief description of the change being made with this pull request.

Motivation

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Additional Notes

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Review checklist (to be filled by reviewers)

• PR title must be written as a CHANGELOG entry (see why)
• Files changes must correspond to the primary purpose of the PR as described in the title (small unrelated changes should have their own PR)
• PR must have changelog/ and integration/ labels attached
• Feature or bugfix must have tests
• Git history must be clean
• If PR adds a configuration option, it must be added to the configuration file.

[codecov]

Codecov Report

Merging #4264 into master will increase coverage by 1.3%.
The diff coverage is 88.88%.

Impacted Files	Coverage Δ
php_fpm/tests/conftest.py	100% <100%> (ø)	⬆️
php_fpm/tests/test_unit.py	100% <100%> (ø)	⬆️
php_fpm/datadog_checks/php_fpm/php_fpm.py	77.11% <81.81%> (-0.76%)	⬇️
...checks_dev/tests/plugin/test_environment_runner.py
riakcs/datadog_checks/riakcs/riakcs.py
oracle/tests/test_oracle.py
...r/datadog_checks/openstack_controller/__about__.py
twistlock/datadog_checks/twistlock/twistlock.py
linkerd/datadog_checks/linkerd/linkerd.py
...oller/datadog_checks/openstack_controller/utils.py
... and 747 more