cleanup web html pages

[joaomoreno]

This reduces the number of HTML files shipped as part of our web from:

/out/vs/code/browser/workbench/callback.html
/out/vs/code/browser/workbench/workbench-dev.html
/out/vs/code/browser/workbench/workbench.html
/out/vs/workbench/contrib/webview/browser/pre/fake.html
/out/vs/workbench/contrib/webview/browser/pre/index-no-csp.html
/out/vs/workbench/contrib/webview/browser/pre/index.html
/out/vs/workbench/services/extensions/worker/webWorkerExtensionHostIframe.html
/extensions/github-authentication/media/index.html
/extensions/microsoft-authentication/media/index.html

to:

/out/vs/workbench/contrib/webview/browser/pre/fake.html
/out/vs/workbench/contrib/webview/browser/pre/index-no-csp.html
/out/vs/workbench/contrib/webview/browser/pre/index.html
/out/vs/workbench/services/extensions/worker/webWorkerExtensionHostIframe.html

[bpasero]

🤔 what about when we serve the web UI from a tunnel as part of our server? Don't we have to ship at least workbench.html and thus callback.html too?

[joaomoreno]

Thanks for taking a look. This PR only affects the web build, which we happen to (1) push to builds.code.visualstudio.com and (2) publish to CDN. It doesn't affect our server+web combo. Does that make sense?

[bpasero]

Ah ok, thanks for clarifying.