Outdated player/lua/osc.lua in mpv_thumbnail_script_client_osc.lua

[elig0n]

Some up-to-date osc.conf options are not recognized by the patched osc.lua file which is embedded in mpv_thumbnail_script_client_osc.lua resulting in warnings like:

mpv_thumbnail_script_client_osc: script-opts/osc.conf:3 unknown key 'boxvideo', ignoring

As a temporary fixup introduce the reported keys under user_opts (defaults can be copied from here).