metrics: Add list of enterprise features to call-home POST

[oleiman]

Flat list of feature names, only those which are currently enabled

Fixes: CORE-8138

Backports Required

• none - not a bug fix
• none - this is a backport
• none - issue does not exist in previous branches
• none - papercut/not impactful enough to backport
• v24.2.x
• v24.1.x
• v23.3.x

Release Notes

• none

[vbotbuildovich]

the below tests from https://buildkite.com/redpanda/redpanda/builds/57562#0192f9a6-0b2e-4433-bb59-775a1466575e have failed and will be retried

datalake_cloud_rpunit

the below tests from https://buildkite.com/redpanda/redpanda/builds/57562#0192f9a6-0b2d-4b21-8079-2ecb7a88f4cf have failed and will be retried

datalake_cloud_rpunit

[michael-redpanda]

@deniscoady check this out

[vbotbuildovich]

/backport v24.2.x

[vbotbuildovich]

/backport v24.1.x

[vbotbuildovich]

Failed to create a backport PR to v24.1.x branch. I tried:

git remote add upstream https://github.com/redpanda-data/redpanda.git
git fetch --all
git checkout -b backport-pr-24004-v24.1.x-440 remotes/upstream/v24.1.x
git cherry-pick -x 4e64125268

Workflow run logs.