refactor: read HTTP/ECDSA outcall cycles from the per-use-case map

[mraszyk]

The cycles consumed by HTTP and ECDSA outcalls are tracked both in the legacy scalar fields consumed_cycles_http_outcalls / consumed_cycles_ecdsa_outcalls of SubnetMetrics and in the consumed_cycles_by_use_case map, which a migration introduced in #10844 keeps in lockstep with those fields.

This switches all readers over to the map:

• get_consumed_cycles_http_outcalls / get_consumed_cycles_ecdsa_outcalls now read the HTTPOutcalls / ECDSAOutcalls entries of consumed_cycles_by_use_case, via a new helper that also backs the existing Schnorr / VetKd / dropped messages getters.
• consumed_cycles_total and consumed_cycles_total_v28 add those entries instead of the scalar fields.

The scalar fields are still observed and serialized, so that downgrading to an earlier replica version keeps observing the correct totals; only their reads are gone.

[zeropath-ai]

✅ No security or compliance issues detected. Reviewed everything up to 7d085c9.

Security Overview

• 🔎 Scanned files: 3 changed file(s)
• 🔗 Scan Link: https://zeropath.com/app/repositories/f5e9d2bb-29a4-4b64-902a-391d65fd8b2d?scanId=adf7edc6-1869-4b72-b049-f7ac11a83c58&codeScanTypes=PrScan&tab=issues

Detected Code Changes

Change Type	Relevant files
Enhancement	► rs/replicated_state/src/metadata_state.rs     Add getters for get_consumed_cycles_http_outcalls and get_consumed_cycles_ecdsa_outcalls ► rs/replicated_state/src/metadata_state.rs     Add get_consumed_cycles_subnet_use_case and migrate_outcalls_cycles_to_use_cases documentation updates
Enhancement	► rs/replicated_state/src/metadata_state/tests.rs     Update tests to reflect migrated use_case entries and updated totals
Enhancement	► rs/replicated_state/src/metrics.rs     Update to use get_consumed_cycles_ecdsa_outcalls and get_consumed_cycles_http_outcalls via subnet metrics getters