feat: pay validators a per-diem rate plus collected fees, and make fees root-settable

[JayWhite2357]

Rationale for this change

We wish for validator rewards to be a governance-adjustable daily rate of total stake, for transaction fees to go to validators instead of being burned, and for transaction costs to be adjustable without a runtime upgrade.

What changes are included in this PR?

• Adds pallet-parameters with a root-settable PerDiemRate.
• Collects transaction fees into CollectedFees instead of burning them.
• EraPayout pays PerDiemRate * total stake per day plus CollectedFees, replacing the hard-coded 9.7% yearly rate; PerDiemRate defaults to the equivalent daily rate (9.7% / 365.25).
• Replaces FeeMultiplierUpdate = (), which zeroes the multiplier, with an explicit ConstFeeMultiplier of 0.
• Makes WeightFeePerRefTime, TransactionByteFee, and FeeMultiplier root-settable, defaulting to current values.

Are these changes tested?

Yes.

[github-actions]

1.70.0

Bug Fixes

• default prover-db indexer to disabled unless explicitly enabled (360803d
• fallback to client hash when is missing (95794da
• make on chain indexer keys saturate rather than default to (5f794de
• rollback to git commit hash 6e668a9 (3d9b9d4
• use finalized block in prover-db-indexer (50438ab

Features

• add helper that queries the client for s. (4fc3952
• add client native interface and extenality (d9c6c4d
• add generic config key-value store for offchain workers (117b845
• add pallet-parameters with root-settable per-diem reward rate (cf9b4a4
• adds (a5b581d
• collect transaction fees in the runtime (caba6cc
• Document Snapshot Download Process (4c2608b
• drop from prover_db_indexer (b3381c5
• make transaction fees root-settable (b878309
• pay validators a per-diem rate of total stake plus collected fees (8729ccd
• register client externality to offchain worker (338c213
• use client for (6679c06
• use generic key value config for prover_db_indexing instead of storage/CLI based config (faff564