Move BlockManager to node/blockstorage

Summary:
Can be reviewed with --color-moved=dimmed-zebra

This is a backport of core#23581
https://github.com/bitcoin/bitcoin/pull/23581/commits/fade2a44f4aabc64185031dbf4c70d875ece6740

Depends on D12487

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D12507