feat(snaps): Add crossAlignment to Box

[GuillaumeRx]

Description

This PR adds the crossAlignment prop to the Snap UI Box component. It generates a align-items property.

Related issues

Fixes: #30368

Manual testing steps

Screenshots/Recordings

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 [448508e]

• 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 (1578 ± 56 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	1365	1834	1580	117	56
		domContentLoaded	1357	1824	1559	114	55
		load	1366	1835	1578	118	56
		domInteractive	23	100	41	24	12
		backgroundConnect	10	65	22	17	8
		firstReactRender	14	83	42	27	13
		getState	4	47	10	12	6
		initialActions	0	1	0	0	0
		loadScripts	941	1360	1131	100	48
		setupStore	7	57	13	14	7
		uiStartup	1528	2324	1824	187	90

[metamaskbot]

Builds ready [de6ee5b]

• 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 (1796 ± 101 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	224	2172	1631	490	235
		domContentLoaded	1469	2149	1771	206	99
		load	1479	2168	1796	210	101
		domInteractive	23	142	49	33	16
		backgroundConnect	9	68	29	18	9
		firstReactRender	14	77	36	22	11
		getState	5	52	23	18	8
		initialActions	0	1	0	0	0
		loadScripts	996	1616	1286	182	87
		setupStore	7	55	17	14	7
		uiStartup	1657	2889	2097	299	143