feat(server): Add support for async server function, module.server, and express module#1842

mconflitti-pbc wants to merge 11 commits intoposit-dev:mainposit-dev/py-shiny:mainfrom

mconflitti-pbc:mconflitti/allow-async-server-funcmconflitti-pbc/py-shiny:mconflitti/allow-async-server-funcCopy head branch name to clipboard