TRST audit fixes for DisputeManager contract

[tmigone]

This PR addresses the following findings:

• TRST-M-7 The Arbitrator could be spammed with a large amount of disputes without any way to be made whole through fees
• TRST-R-10 Verify addresses are non-zero before use
• TRST-R-9 Documentation errors

[openzeppelin-code]

TRST audit fixes for DisputeManager contract

Generated at commit: 8aa05c44ec3608229d8f6f85a7bdb4fd07f92f4b

🚨 Report Summary

	Severity Level	Results
Contracts	Critical High Medium Low Note Total	2 5 0 15 39 61
Dependencies	Critical High Medium Low Note Total	0 0 0 0 0 0

---

For more details view the full report in OpenZeppelin Code Inspector