Collect value-only application tags

[ChristineTChen]

What does this PR do?

Currently the yarn integration will skip parsing application tags if they're not in key:value form.

Motivation

Value tags are technically valid tags and should be collected: see docs

Currently the logs are getting skipped and submitted as a long string

2022-01-26 16:02:51 UTC | CORE | WARN | (pkg/collector/python/datadog_agent.go:124 in LogMessage) | yarn:c21bd3c1c88284c2 | (yarn.py:279) | Unable to split string luigiscript_name:dash_monitor_edge,livy-batch-0-5hmfsykz,user_email:data-science-eng with YARN application tags

Additional Notes

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• 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

[ofek]

Is this also affected? https://github.com/DataDog/integrations-core/blob/7.34.x/spark/datadog_checks/spark/spark.py#L443-L472