fix: Move foreground state properties from metamask slice to appState slice

[MajorLift]

Description

1. Moves properties in the metamask Redux slice that are not part of background (i.e. controller-derived) state into the appState slice.

The affected state properties are as follows:

  customNonceValue: string;
  isAccountMenuOpen: boolean;
  isNetworkMenuOpen: boolean;
  nextNonce: string | null;
  pendingTokens: {
    [address: string]: Token & { isCustom?: boolean; unlisted?: boolean };
  };
  welcomeScreenSeen: boolean;
  confirmationExchangeRates: ContractExchangeRates;

• Foreground properties that are a part of AppStateController state have not been moved into the appState slice, and will remain in the unflattened metamask slice.
  • It's not immediately clear why the properties listed above were excluded from AppStateController state, but since all of them appear to neither require persistence beyond a given session, nor anonymization of PII, I'm opting to leave them out of controller state.
• The isInitialized property is not included, because it's derived from background state before the Redux store is instantiated, and is updated by the PatchStore which supplies it directly to the metamask slice.

2. Consolidates appState slice selectors from ui/selectors/selectors.js and ui/app/app.ts to ui/app/selectors.ts.

Related issues

• Closes https://github.com/MetaMask/MetaMask-planning/issues/2895
• Blocking https://github.com/MetaMask/MetaMask-planning/issues/2894
  • perf: Unflatten MetamaskController stores (1/5) #28723
  • perf: Unflatten metamask Redux slice and convert to TypeScript (2/5) #28929
  • perf: Unflatten downstream references to metamask Redux slice (5/5) #28776

Manual testing steps

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.

[github-actions]

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[mcmire]

This seems pretty straightforward to me. Nothing jumped out at me.

[metamaskbot]

Builds ready [537fef8]

• 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 (1944 ± 69 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	1756	2219	1944	142	68
		domContentLoaded	1706	2188	1911	148	71
		load	1743	2222	1944	144	69
		domInteractive	26	86	35	13	6
		backgroundConnect	8	97	34	23	11
		firstReactRender	16	91	35	28	14
		getState	79	393	161	79	38
		initialActions	0	0	0	0	0
		loadScripts	1306	1686	1494	120	58
		setupStore	7	19	9	3	1
		uiStartup	1970	2965	2305	260	125

Bundle size diffs [🚀 Bundle size reduced!]

• background: 0 Bytes (0.00%)
• ui: -130 Bytes (-0.00%)
• common: -54 Bytes (-0.00%)

[metamaskbot]

Builds ready [f2da87c]

• 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 (1917 ± 98 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	1673	2555	1921	208	100
		domContentLoaded	1648	2543	1894	201	96
		load	1676	2558	1917	203	98
		domInteractive	25	60	33	10	5
		backgroundConnect	9	68	27	17	8
		firstReactRender	15	88	22	15	7
		getState	100	292	134	40	19
		initialActions	0	0	0	0	0
		loadScripts	1259	2056	1479	172	82
		setupStore	6	24	10	4	2
		uiStartup	1904	2966	2214	248	119

Bundle size diffs [🚀 Bundle size reduced!]

• background: 0 Bytes (0.00%)
• ui: -130 Bytes (-0.00%)
• common: -54 Bytes (-0.00%)