Add OSD metadata tags

[mxmeinhold]

What does this PR do?

Pull several values from osd metadata as tags. This separates metrics by device ID, class, objectstore, and ceph version

Motivation

We've been using these tags to track a couple of migrations in our ceph cluster, including hdd to ssd upgrades, filestore to bluestore, and version upgrades, as well as identifying problematic drives using device identifiers.

Additional Notes

This is based on my patch files, so I haven't yet gotten tests/integration into the repo cleanly. I haven't had luck getting a dev environment set up on my personal laptop in the past, so I'll need to give that another try

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
• If the PR doesn't need to be tested during QA, please add a qa/skip-qa label.

[github-actions]

Test Results

  4 files    4 suites   3m 38s ⏱️
11 tests 11 ✔️ 0 💤 0 ❌
24 runs  22 ✔️ 2 💤 0 ❌

Results for commit f8e1864.

♻️ This comment has been updated with latest results.

[mxmeinhold]

Docs said to install python 3.8, but it looks like the tests are failing on f-strings in py 2.7.4?

[codecov]

Codecov Report

Merging #14201 (f8e1864) into master (18c6a0c) will increase coverage by 0.00%.
The diff coverage is 100.00%.

Flag	Coverage Δ
ceph	91.07% <100.00%> (+0.04%)	⬆️

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

[yzhan289]

Thanks for this PR! Could you add a test? You should be able to spin up a ceph env using ddev, our CLI tool for making integrations. Once you set up ddev, you can run something like ddev env start ceph py3.8-5.0 (other versions can be found here).