3222 estimate user reward for layer

[abergasov]

Motivation

Closes #3222

Changes

implement endpoint, which try estimate reward for layer X.

for past layers - simply look at db. for current or future layers - calc it from weight and activations

pr for api modify https://github.com/spacemeshos/api/pull/167

Test Plan

TODO

• [ ] Explain motivation or link existing issue(s)
• [ ] Test changes and document test plan
• [ ] Update documentation as needed

DevOps Notes

• [x] This PR does not require configuration changes (e.g., environment variables, GitHub secrets, VM resources)
• [x] This PR does not affect public APIs
• [x] This PR does not rely on a new version of external services (PoET, elasticsearch, etc.)
• [x] This PR does not make changes to log messages (which monitoring infrastructure may rely on)