feat: Implement speed row in gas-fee-estimates

[OGPoyraz]

Description

This PR aims to implement "speed" row in gas fee estimates. See recording - we change gas values and speed row is changing.

Since these transactions are not reachable in the current user flow - adding no e2e test as it's not required.

Related issues

Fixes: https://github.com/MetaMask/MetaMask-planning/issues/5023

Manual testing steps

1. Go send flow while transfer redesigned transfer confirmations enabled
2. See speed row under network fee

Screenshots/Recordings

Before - no speed row

After - with speed row

Simulator.Screen.Recording.-.iPhone.15.Pro.-.2025-05-30.at.09.43.37.mp4

Pre-merge author checklist

• I’ve followed MetaMask Contributor Docs and MetaMask Mobile Coding Standards.
• I've completed the PR template to the best of my ability
• 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.

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.

[sonarqubecloud]

Quality Gate passed

Issues
2 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud