Adding sandbox pre-reqs to the setting UI for linux

[dileepyavan]

fixes:#291022
For linux, bubblewrap, socat and ripgrep should be installed. Updated the setting UI to show this

[Copilot]

Pull request overview

This PR updates the terminal sandbox settings descriptions to surface required tooling so users understand the prerequisites for enabling the sandbox, especially on Linux. The changes are limited to configuration metadata used by the Settings UI.

Changes:

• Updated the Linux terminal sandbox file system setting description to note that bubblewrap, socat, and ripgrep must be installed.
• Updated the macOS terminal sandbox file system setting description to note that ripgrep must be installed.

Comments suppressed due to low confidence (1)

src/vs/workbench/contrib/terminalContrib/chatAgentTools/common/terminalChatAgentToolsConfiguration.ts:577

• The macOS sandbox description also has spacing issues: there should be a space after "macOS." and a space before the parenthesis in "patterns (ex: …)". Cleaning this up will make the user-facing text read more naturally and match the Linux description style.

		markdownDescription: localize('terminalSandbox.macFileSystemSetting', "Note: this setting is applicable only when {0} is enabled. Controls file system access in the terminal sandbox on macOS.Paths also support git-style glob patterns(ex: *.ts, ./src, ./src/**/*.ts, file?.txt). **ripgrep** should be installed for this setting to work.", `\`#${TerminalChatAgentToolsSettingId.TerminalSandboxEnabled}#\``),