chore: update security related commands

Description

This MR fixes two issues with security-related commands in vscode extension

1. Command, gl.viewSecurityFinding, shows up in the command palette which opens an empty tab.

   Unintended use-case through Command Palette	Intended use-case showing security finding details upon clicking the item (!982 (merged))

   • This command expects a security finding item to display in the webview. Its use case is to select a security finding from the sidebar and open up a tab with details.
   • Hiding the command as I don't think it was intended to show up in the command palette.

2. Command, gl.runSecurityScan, was dependent on the wrong config 😭 Fixing to refer to the correct one - config.gitlab.real-timeSecurityScan.enabled

Related Issues

Resolves #[issue_number]

How has this been tested?

• If src/browser or src/common has been modified, please consider interoperability with the Web IDE. See Running the Extension in WebIDE.
• Consider an end-to-end test for significant new features that aren't covered by integration tests.

Screenshots (if appropriate)

What CHANGELOG entry will this MR create?

• fix: Bug fix fixes - a user-facing issue in production - included in changelog
• feature: New feature - a user-facing change which adds functionality - included in changelog
• BREAKING CHANGE: (fix or feature that would cause existing functionality to change) - should bump major version, mentioned in the changelog
• None - other non-user-facing changes