refactor(NetworkPrefabHandler): reduce effort cognitive for understand this

[MarcusSilvaDev]

Some points fixed:

• Reduce nested if.
• Reduce complexity cyclomatic.
• add Guard clauses.

[unity-cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 2 committers have signed the CLA.

✅ MarcusViniciusSS
❌ Marcus.Silva

---

Marcus.Silva seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[EmandM]

Closing this as the changes are out of date.