[v24.2.x] [CORE-7152] Admin: Introduce GET /v1/features/enterprise endpoint

[vbotbuildovich]

Backport #23314 to branch v24.2.x. Note that this issue was created as a placeholder, since the original PR's commit(s) could not be automatically cherry-picked.
Here are the commands to execute:

git checkout v24.2.x
git checkout -b vbotbuildovich/backport-23314-v24.2.x-830
git cherry-pick -x bf972c04d80c297ed9322e2e6501cb8cda9ec63f 067df42f1df3d30b50230d1c3df34efaafc276ae 653d5a979aba1e50f37dee31b6cf231fb1fcafc8 d6e33cd177f87c52c847e7398a9384c73c6d34b3 5fdc1782506e85d43c05b06f4551f5627017494a b5c06fa59d7c149bdb5b723592f16c4d04a5db64 ebfdd7fe27a4f441e2379397501c639420724fc1

git push origin vbotbuildovich/backport-23314-v24.2.x-830
gh pr create \
  --title "[v24.2.x] [CORE-7152] Admin: Introduce `GET /v1/features/enterprise` endpoint" \
  --base "v24.2.x" \
  --label "kind/backport" \
  --head "vbotbuildovich/backport-23314-v24.2.x-830" \
  --draft \
  --repo "redpanda-data/redpanda" \
  --milestone "v24.2.x-next" \
  --body "Backport of PR https://github.com/redpanda-data/redpanda/pull/23314 "

[CORE-7152]: https://redpandadata.atlassian.net/browse/CORE-7152?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

JIRA Link: [CORE-7342](https://redpandadata.atlassian.net/browse/CORE-7342)

[oleiman]

Closed by #23368