sql_browser: use monaco editor

Use monaco editor with https://github.com/joe-re/sql-language-server
completion provider bundled in
https://lab.nexedi.com/jerome/monaco-editor-sql-completion-provider
This completion provider is not perfect, but codemirror's one was not so
good eiher. At least we can use monaco editor.

Also add a quick "copy to cliboard" feature, which copies the table as
html or in markdown format for text.

And also fix Server-Timing header that was an obsolete syntax no longer
supported by chrome.