DAL: simplify recording of attested slots
What
Closes #3109 (closed).
Two small optimizations:
- only record the number of attested shards instead the exact shards
- use a map instead of a list for recording attested shards
Why
The first commit both improves the performance (probably negligibly) and simplifies the code.
The second one simply avoids a List.nth.
Manually testing the MR
The CI should be sufficient.
Edited by Eugen Zalinescu