fix: token.icon possibly null, update validators and types

[infiniteflower]

Description

This PR fixes an issue where token.icon returned by the Bridge API status endpoint could be null, which caused validation to fail. It updates the types and the validation to match what the Bridge API returns.

Related issues

Related to #28899

Manual testing steps

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Screenshots/Recordings

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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.

[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 [69efdb6]

• 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: Background Module Init Stats
• mv3: UI Init Stats
• mv3: Module Load Stats
• 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
  • 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 (1999 ± 83 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	1626	2293	2006	179	86
		domContentLoaded	1587	2275	1973	174	83
		load	1624	2290	1999	173	83
		domInteractive	26	67	38	11	5
		backgroundConnect	8	79	27	21	10
		firstReactRender	16	30	20	3	2
		getState	112	387	156	68	33
		initialActions	0	1	0	0	0
		loadScripts	1186	1794	1534	153	74
		setupStore	7	79	16	21	10
		uiStartup	1853	3094	2361	268	129

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

• background: 17 Bytes (0.00%)
• ui: 0 Bytes (0.00%)
• common: 0 Bytes (0.00%)

[MainS2020]

Ok

[metamaskbot]

Builds ready [46e7e8d]

• 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: Background Module Init Stats
• mv3: UI Init Stats
• mv3: Module Load Stats
• 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
  • 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 (2092 ± 86 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	1876	2592	2088	173	83
		domContentLoaded	1831	2577	2060	180	86
		load	1876	2595	2092	179	86
		domInteractive	27	68	40	12	6
		backgroundConnect	10	81	31	23	11
		firstReactRender	16	35	22	5	2
		getState	102	179	136	19	9
		initialActions	0	1	0	0	0
		loadScripts	1429	1984	1632	141	68
		setupStore	7	13	9	2	1
		uiStartup	2110	3009	2414	222	107

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

• background: 17 Bytes (0.00%)
• ui: 0 Bytes (0.00%)
• common: 0 Bytes (0.00%)

[metamaskbot]

Builds ready [376e210]

• 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: Background Module Init Stats
• mv3: UI Init Stats
• mv3: Module Load Stats
• 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
  • 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 (1726 ± 64 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	1501	2075	1729	133	64
		domContentLoaded	1484	2003	1696	127	61
		load	1503	2026	1726	133	64
		domInteractive	26	70	34	11	5
		backgroundConnect	10	67	30	20	10
		firstReactRender	17	80	36	24	11
		getState	5	59	20	18	9
		initialActions	0	1	0	0	0
		loadScripts	1076	1563	1278	112	54
		setupStore	6	59	16	17	8
		uiStartup	1711	2445	1950	164	79

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

• background: 17 Bytes (0.00%)
• ui: 0 Bytes (0.00%)
• common: 0 Bytes (0.00%)