Hierarchical state diffs in hot DB (#6750)

This PR implements https://github.com/sigp/lighthouse/pull/5978 (tree-states) but on the hot DB. It allows Lighthouse to massively reduce its disk footprint during non-finality and overall I/O in all cases.

Closes https://github.com/sigp/lighthouse/issues/6580

Conga into https://github.com/sigp/lighthouse/pull/6744

### TODOs

- [x] Fix OOM in CI https://github.com/sigp/lighthouse/pull/7176
- [x] optimise store_hot_state to avoid storing a duplicate state if the summary already exists (should be safe from races now that pruning is cleaner)
- [x] mispelled: get_ancenstor_state_root
- [x] get_ancestor_state_root should use state summaries
- [x] Prevent split from changing during ancestor calc
- [x] Use same hierarchy for hot and cold

### TODO Good optimization for future PRs

- [ ] On the migration, if the latest hot snapshot is aligned with the cold snapshot migrate the diffs instead of the full states.
```
align slot  time
10485760    Nov-26-2024
12582912    Sep-14-2025
14680064    Jul-02-2026
```

### TODO Maybe things good to have

- [ ] Rename anchor_slot https://github.com/sigp/lighthouse/compare/tree-states-hot-rebase-oom...dapplion:lighthouse:tree-states-hot-anchor-slot-rename?expand=1
- [ ] Make anchor fields not public such that they must be mutated through a method. To prevent un-wanted changes of the anchor_slot

### NOTTODO

- [ ] Use fork-choice and a new method [`descendants_of_checkpoint`](ca2388e196 (diff-046fbdb517ca16b80e4464c2c824cf001a74a0a94ac0065e635768ac391062a8)) to filter only the state summaries that descend of finalized checkpoint]

account_manager/src/validator/slashing_protection.rs

@@ -90,7 +90,7 @@ pub fn cli_run<E: EthSpec>(
             let slashing_protection_database =
                 SlashingDatabase::open_or_create(&slashing_protection_db_path).map_err(|e| {
                     format!(
-                        "Unable to open database at {}: {:?}",
+                        "Unable to open slashing protection database at {}: {:?}",
                         slashing_protection_db_path.display(),
                         e
                     )
@@ -198,7 +198,7 @@ pub fn cli_run<E: EthSpec>(
             let slashing_protection_database = SlashingDatabase::open(&slashing_protection_db_path)
                 .map_err(|e| {
                     format!(
-                        "Unable to open database at {}: {:?}",
+                        "Unable to open slashing protection database at {}: {:?}",
                         slashing_protection_db_path.display(),
                         e
                     )