Transform the only Lua template of the status module into an equivalent
ucode template and make it conditionally include the legacy Lua logic
factored out in a previous commit.
Only if the ucode Lua bridge is installed and loadable, the Lua template
loading the legacy Lua status partials is included.
After this commit, luci-mod-status is free of Lua dependencies.
Signed-off-by: Jo-Philipp Wich <jo@mein.io>