use flexbox for list/details layout, no more float and absolute positions, fixes https://github.com/microsoft/vscode/issues/90053 and fixes https://github.com/microsoft/vscode/issues/102089

cleanup, also allow to untoggle details on every item, fixes https://github.com/microsoft/vscode/issues/90094

and clear execution metadata for "clear all outputs"
Fix #107908

Fixes #108000

Fix a bypass for CVE-2020-16881

Fixes #107951

Uses child_process.execFile() rather than child_process.exec() to more
effectively resolve the command injection vulnerability.

According to:
https://docs.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-auth-code-flow#successful-response-1

Auto detect color scheme sets one theme for all open windows despite different preferred schemes set in workspaces. Fixes #107855

OS color schemes: report hc and light/dark

Get #107909 back to where it was in 1.49