chore: add ls webview url check

Description

We are occasionally getting reports with LS Duo Chat initialization timed out error.

The root cause is unclear at the moment. Let's add new check and logging to help debug this.

• Add check if webview url is available.
• Add logging to indicate if url is available or not to quickly determine if webview initialization error is caused by missing the url.

Related Issues

#1091 and #1087

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.

Manually tested

Invalid URL logs

2025-05-16T12:29:16:731 [error]: Error checking gl.webview.duo-chat-v2 url: http://127.0.0.1:8000/
2025-05-16T12:29:16:732 [debug]: gl.webview.duo-chat-v2 url is not available

Valid URL logs

2025-05-16T12:31:06:302 [debug]: gl.webview.duo-chat-v2 url is available

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