fix: circular dependency for initial global root update (#1499)

**Motivation:**

`OperatorTableUpdater` currently has a bug where the first global root
update can't be completed due to `BN254CertificateVerifier` requiring a
valid global root.

**Modifications:**

Initialization now adds a dummy global table root.

**Result:**

Bug fixed

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Co-authored-by: Yash Patil <[email protected]>

Author: eigenmikem