[v23.1.x] Limit memory used while fetching many partitions

[vbotbuildovich]

Backport #10905 to branch v23.1.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 v23.1.x
git checkout -b vbotbuildovich/backport-10905-v23.1.x-424
git cherry-pick -x 1db2edcd91fd7e692d069b1c059a03c353a8c689 ee5e069e3623dd655688df2d2db75c59a11b63f5 eb8a915a9497e6594ba712b0de58109d176c68bd d891efe7fc3dbc0ef27b17a53946336e17759296 58a9de0f0e32537f879404f3a4633fd5e94ed879 7b3860153a544aedd97a94a4d221ae034cf0439d d3d9276237a4c6f4ff3246c85ad3af40fc1e522e c1d77cd216d78e935586fac16274671329b70d97 2474ef67ed1e078cab1011e8835a47e71cede509 623e6136b35c4331a0a39aed1d9508edb8a7f5e0 950abc7d8ddaff656cfd035a061a999479b0a09e 06a38b97cfde550dcde20f6989ebc150750923e7

git push origin vbotbuildovich/backport-10905-v23.1.x-424
gh pr create \
  --title "[v23.1.x] Limit memory used while fetching many partitions" \
  --base "v23.1.x" \
  --label "kind/backport" \
  --head "vbotbuildovich/backport-10905-v23.1.x-424" \
  --draft \
  --repo "redpanda-data/redpanda" \
  --reviewer "jcsp,travisdowns,graphcareful" \
  --milestone "v23.1.x-next" \
  --body "Backport of PR https://github.com/redpanda-data/redpanda/pull/10905 "

[BenPope]

Fixed by #11858