feat: display full terms of service during onboarding

[jonybur]

Description

During the onboarding process, the user is currently presented with a simple checkbox to agree to terms:

Legal would prefer we show the full terms of service, requiring the user to scroll the entire terms and agree at the end.

Related issues

Fixes: https://github.com/MetaMask/MetaMask-planning/issues/3013

Manual testing steps

1. Start onboarding
2. See checkbox but without full terms.
3. Verify full terms are displayed, requiring user to scroll and agree.

Screenshots/Recordings

Before

After

demo.mp4

No response

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.

[metamaskbot]

Builds ready [5d2206e]

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

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

Page Load Metrics (1771 ± 70 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	242	2089	1706	361	173
		domContentLoaded	1482	2076	1740	146	70
		load	1487	2092	1771	145	70
		domInteractive	26	224	62	47	23
		backgroundConnect	10	85	36	23	11
		firstReactRender	17	76	30	18	9
		getState	5	59	17	16	8
		initialActions	0	1	0	0	0
		loadScripts	1063	1651	1310	132	63
		setupStore	8	55	25	20	9
		uiStartup	1716	2364	2031	160	77