[SI] VaultHubViewer contract

[DiRaiks]

A short summary of the changes.

Context

This PR introduces the VaultHubViewerV1 contract for read-only interactions with the VaultHub. It provides methods to:

• Check vault ownership: isOwner verifies if an address is the owner of a vault.
• Check role assignments: isHasRole checks if an address holds a specific role in a vault.
• Retrieve vaults by ownership: vaultsByOwner returns vaults owned by a given address.
• Retrieve vaults by role: vaultsByRole returns vaults where an address holds a specified role.
• Filter zero vaults: _filterNonZeroVaults ensures only valid vaults are included.

The contract works with the IVaultHub interface. It also includes the ZeroArgument error for invalid zero address inputs.

Key Features:

• Immutable vaultHub address.
• Non-state-changing queries for vault information.

This contract offers a simple, efficient way to query vaults and roles without affecting the state.

Problem

What problem this PR solves, link relevant issue if it exists

Solution

Your proposed solution

[tamtamchik]

👀 Added some comments for further optimizations

[tamtamchik]

It could be worth moving inside IStakingVault. Looks like may be used often.

[Jeday]

owner here conflicts when moving to IStakingVault, because StakingVault is IStakingVault, ..., Ownable