feat: tackle all remaining no-non-null-assertion lint errors

[gomesalexandre]

Description

Fixes all remaining offenders of no-non-null-assertion so we can finally bring this guy in 🎉

• tackle all
• tsc fix

Issue (if applicable)

closes #8909

Risk

Technically high because of the number of domains touched, in reality should be fairly low-risk

High Risk PRs Require 2 approvals

What protocols, transaction types, wallets or contract interactions might be affected by this PR?

Technically low, this makes things safer theoretically but effectively medium/high because of the surface area

Testing

Do a full app smoke test focusing on:

• Tx history (nuke your cache beforehand to ensure we're parsing everything from scratch)
• Fiat ramps
• Balance charts (including rainbow charts)
• Send modal
• "Add Account" modal
• RFOX (e2e testing)

Engineering

• ☝🏽

Operations

• 🏁 My feature is behind a flag and doesn't require operations testing (yet)

• ☝🏽

Screenshots (if applicable)

Tx history (nuke your cache beforehand to ensure we're parsing everything from scratch)

Fiat ramps

0d891e-91da-4f5c-9c8c-0d53de484d43

Balance charts (including rainbow charts)

https://jam.dev/c/e0b11104-bd5c-473a-909c-98797f2d10ae

• Send modal

https://jam.dev/c/dfd05f2e-62c0-4677-bd13-ad1ca9cdaf04

• "Add Account" modal

https://jam.dev/c/e2cb8178-bd00-4110-9fd1-95a426276ed6

• RFOX (e2e testing)

https://jam.dev/c/540d9751-7030-47c9-a74b-55d5343cf8f1