feat: private destroy variable of Network Controller

[tommasini]

Explanation

References

Relates to the upgrade on mobile to controllers v53: https://github.com/MetaMask/metamask-mobile/pull/7999

Changelog

@metamask/network-controller

• <ADDED>: Add internal destroyed variable to stop on going lookupNetwork function.

Checklist

• [ ] I've updated the test suite for new or updated code as appropriate
• [ ] I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• [ ] I've highlighted breaking changes using the "BREAKING" category above as appropriate