Fix typos

[Dimitrolito]

This pull request addresses typos in the following files:

• DABridgeRouter.sol: Corrected an instance of "an Nomad" to "a Nomad" for grammatical accuracy.
• XAppConnectionClient.sol: Fixed "an Nomad Replica contract" to "a Nomad Replica contract."
• utils.ts: Updated "an Nomad ID" to "a Nomad ID" in the comment for consistency.

These changes improve the clarity and correctness of the code documentation.