fix: Transaction Details view shows inaccurate balance on Mobile

[salimtb]

Description

users have discrepancy in the USDT token balance on his tx insight page in the MM app, they are seeing 33.22 USDT but it should be 5.43 USDT ( see the pictures below )

the problem is due to the fact that we use a hexadecimal value to create a big number object, whereas the function balanceToFiat expects a decimal value. to calculate the conversion fiat

Related issues

Fixes: #7787

Manual testing steps

1. Go to the main page of the app and click on your USDT token.
2. scroll down and click on "Received USDT"
3. check the amount section

Screenshots/Recordings

Before

https://drive.google.com/file/d/1766q37UBdndVqk0cNG8eVCBf-mCsCm2j/view?usp=sharing

After

https://drive.google.com/file/d/1l_sC7CK67WbjQmtLpbFUqiqj4iie2Fqv/view?usp=sharing

Pre-merge author checklist

• I’ve followed MetaMask Coding Standards.
• I've clearly explained what problem this PR is solving and how it is solved.
• I've linked related issues
• I've included manual testing steps
• I've included screenshots/recordings if applicable
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.
• I’ve properly set the pull request status:
  • In case it's not yet "ready for review", I've set it to "draft".
  • In case it's "ready for review", I've changed it from "draft" to "non-draft".

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[github-actions]

E2E test started on Bitrise: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/a95cd78b-a42c-4fa5-ab99-ccd2f9d0eeeb
You can also kick off another Bitrise E2E smoke test by removing and re-applying the (Run Smoke E2E) label

[tommasini]

Is there an issue already created on github that we can link for this bug?

[salimtb]

Is there an issue already created on github that we can link for this bug?

hey @tommasini ,
you can find here the github issue link

[github-actions]

E2E test started on Bitrise: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/8ab2e482-8050-44c8-ad52-fe215975de3f
You can also kick off another Bitrise E2E smoke test by removing and re-applying the (Run Smoke E2E) label

[sonarcloud]

Quality Gate passed

The SonarCloud Quality Gate passed, but some issues were introduced.

1 New issue
0 Security Hotspots
100.0% Coverage on New Code
20.0% Duplication on New Code

See analysis details on SonarCloud

[tommasini]

lGTM