fix (cherry-pick): Add transaction simulation supported networks global mock (#30507)

[danjm]

Cherry-picks ff041ab to v12.13.0.

Original PR description:

Description

A global mock has been added for the "supported networks" check made as part of the transaction simulations feature. This is triggered by certain types of confirmations (those that support transaction simulations), so it's triggered by a wide variety of E2E tests.

Related issues

Fixes #30490

Manual testing steps

This should resolve the privacy snapshot related errors on CI.

You could also double-check that the mocked response is returned by running an e2e test locally that uses a confirmation that supports transaction simulation, then inspecting the network tab of the service worker dev console while the test is running, and checking the response to the
https://tx-sentinel-ethereum-mainnet.api.cx.metamask.io/networks call

Screenshots/Recordings

N/A

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Extension 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.

---

Description

Related issues

Fixes:

Manual testing steps

1. Go to this page...

Screenshots/Recordings

Before

After

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Extension 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.

[metamaskbot]

Builds ready [f175c78]

• builds: chrome, firefox
• builds (flask): chrome, firefox
• builds (MMI): chrome
• builds (test): chrome, firefox
• builds (test-flask): chrome, firefox
• build viz: Build System
• mv3: Bundle Size Stats
• mv2: E2e Actions Stats
• storybook: Storybook
• typescript migration: Dashboard
• all artifacts
• bundle viz:

  • background: 0, 1, 2, 3, 4, 5, 6, 7
  • common: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
  • ui: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
  • content-script: 0
  • offscreen: 0

Page Load Metrics (1918 ± 163 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	1506	2804	1925	345	166
		domContentLoaded	1499	2758	1901	335	161
		load	1517	2784	1918	339	163
		domInteractive	23	197	57	43	21
		backgroundConnect	10	49	20	13	6
		firstReactRender	14	76	34	21	10
		getState	5	100	28	27	13
		initialActions	0	1	0	0	0
		loadScripts	1049	2117	1386	281	135
		setupStore	7	61	25	21	10
		uiStartup	1695	3199	2213	387	186

[metamaskbot]

No release label on PR. Adding release label release-12.13.0 on PR, as PR was cherry-picked in branch 12.13.0.