[Bug]: Confusables logic does not evaluate combinations of letters

### Describe the bug

Creating this issue to track what I reported in mobile: https://github.com/MetaMask/metamask-mobile/issues/5415

### Steps to reproduce

1. Attempt to send assets to metarnask.eth and observe lack of highlighting on the letters "rn" that masquerade as a lower case "m"

### Error messages or log output

_No response_

### Version

10.22.2

### Build type

None

### Browser

Firefox

### Operating system

MacOS

### Hardware wallet

_No response_

### Additional context

ventura 13.0.1 with firefox 108.0.1

Reproduce the report in Firefox 108.0.1 with the example address "metarnask.eth", and read the linked MetaMask Mobile issue 5415 for related context. Done means the combined letters "rn" that masquerade as a lowercase "m" are highlighted when the address is evaluated.

Written by the indexing model from the issue text.