Add state proof table to key registry

[winder]

Summary

Allocate a spot in the key registry for state proofs. This is not used yet but should allow us to add them when we are ready.

Test Plan

Existing tests should detect any regression.

[codecov-commenter]

Codecov Report

Merging #3156 (d8dff86) into feature/partkey (25c8f26) will decrease coverage by 0.02%.
The diff coverage is 33.33%.

@@                 Coverage Diff                 @@
##           feature/partkey    #3156      +/-   ##
===================================================
- Coverage            44.12%   44.10%   -0.03%     
===================================================
  Files                  394      394              
  Lines                87601    87604       +3     
===================================================
- Hits                 38654    38635      -19     
- Misses               42855    42874      +19     
- Partials              6092     6095       +3     

Impacted Files	Coverage Δ
data/account/participationRegistry.go	81.44% <33.33%> (-0.38%)	⬇️
agreement/cryptoVerifier.go	75.73% <0.00%> (-2.21%)	⬇️
agreement/proposalManager.go	96.07% <0.00%> (-1.97%)	⬇️
network/requestTracker.go	70.25% <0.00%> (-1.30%)	⬇️
catchup/service.go	69.32% <0.00%> (-1.25%)	⬇️
ledger/blockqueue.go	83.90% <0.00%> (-1.15%)	⬇️
data/abi/abi_type.go	92.03% <0.00%> (-1.00%)	⬇️
network/wsPeer.go	70.66% <0.00%> (-0.80%)	⬇️

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[id-ms]

we need to construct an index for the round (I.e we want to SELECT according to round)

[winder]

With the registry, we'll need to select on (pk, round), which is the primary key. Since that's the primary key we shouldn't need another index.