[v23.3.x] CORE-1972 don't mark rebalance complete if some partitions are not moveable

[vbotbuildovich]

Backport https://github.com/redpanda-data/redpanda/pull/18489 to branch v23.3.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 v23.3.x
git checkout -b vbotbuildovich/backport-18489-v23.3.x-373
git cherry-pick -x 39a5ec43243421f1345d7c9bab7e8ab5102fd526 46e7a589ec7810c05095d65dff049f91d24c29ac d54e6b6eb87293884e1d3ad6b8139265b8f0c561 588ca47c3d5373937b4c20c83b02b6c597fb3ebd

git push origin vbotbuildovich/backport-18489-v23.3.x-373
gh pr create \
  --title "[v23.3.x] CORE-1972 don't mark rebalance complete if some partitions are not moveable" \
  --base "v23.3.x" \
  --label "kind/backport" \
  --head "vbotbuildovich/backport-18489-v23.3.x-373" \
  --draft \
  --repo "redpanda-data/redpanda" \
  --milestone "v23.3.x-next" \
  --body "Backport of PR https://github.com/redpanda-data/redpanda/pull/18489 "

JIRA Link: [CORE-2980](https://redpandadata.atlassian.net/browse/CORE-2980)