Re-introduces chain id to SS and commitment store

[LeoPatOZ]

This allows the SS to be deployed to multiple chains whilst ensuring signals can be verified against their source chain (this prevents eth deposits to be redeemed on multiple chains for example)

[github-actions]

Changes to gas cost

Generated at commit: 945984cc5a965c4d0213d25cfb207457fdb5ca3e, compared to commit: a9b795fecea7b1132de8b9f3b58c14b7e3743dd3

🧾 Summary (10% most significant diffs)

Contract	Method	Avg (+/-)	%
CheckpointTracker	proveTransition	+665 ❌	+0.64%
ProverManager	prove	+668 ❌	+0.52%

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Full diff report 👇

Contract	Deployment Cost (+/-)	Method	Min (+/-)	%	Avg (+/-)	%	Median (+/-)	%	Max (+/-)	%	# Calls (+/-)
CheckpointTracker	984,197 (+4,760)	proveTransition	104,049 (+665)	+0.64%	104,049 (+665)	+0.64%	104,049 (+665)	+0.64%	104,049 (+665)	+0.64%	1 (0)
ProverManager	2,854,862 (0)	prove	105,854 (+668)	+0.64%	127,912 (+668)	+0.52%	129,789 (+668)	+0.52%	142,470 (+668)	+0.47%	6 (0)
SignalService	4,286,056 (+94,187)	setAuthorizedCommitter	47,624 (+22)	+0.05%	47,624 (+22)	+0.05%	47,624 (+22)	+0.05%	47,624 (+22)	+0.05%	22 (0)