Use workspace tsdk settings without an additional prompt

[Copilot]

Trusted workspaces currently require a second confirmation before using a tsdk configured in workspace settings.

• Behavior: Use workspace-configured SDKs automatically when the workspace is trusted.
• Security: Continue rejecting workspace SDKs in untrusted workspaces.
• Preferences: Preserve explicit opt-outs and previously suppressed prompts.
• Coverage: Add focused tests for trust and persisted preference combinations.

{
    "js/ts.tsdk.path": "./node_modules/typescript/lib"
}

• Fixes Allow settings.json to configure tssdk without a prompt #63882