fix: Add transaction simulation supported networks global mock

[Gudahtt]

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.

[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.

[DDDDDanica]

LGTM !

[metamaskbot]

Builds ready [e05b2c1]

• 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 (1808 ± 89 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	120	2107	1635	490	235
		domContentLoaded	1541	2314	1776	179	86
		load	1550	2319	1808	185	89
		domInteractive	25	147	46	31	15
		backgroundConnect	12	70	34	19	9
		firstReactRender	15	79	37	24	12
		getState	6	66	24	20	9
		initialActions	0	1	0	0	0
		loadScripts	1132	1852	1332	165	79
		setupStore	7	53	14	9	5
		uiStartup	1805	2576	2071	194	93

Bundle size diffs [🚨 Warning! Bundle size has increased!]

• background: 0 Bytes (0.00%)
• ui: 0 Bytes (0.00%)
• common: 94 Bytes (0.00%)

[metamaskbot]

Missing release label release-12.13.0 on PR. Adding release label release-12.13.0 on PR and removing other release labels(release-12.14.0), as PR was cherry-picked in branch 12.13.0.