[StaticRoute] Remove redundant `_sendfile` coroutine & future proof `sendfile` for RANGE support.
[StaticRoute] Remove redundant `_sendfile` coroutine & future proof `sendfile` for RANGE support.

z2v/aiohttp,jashandeep-sohi/aiohttp,juliatem/aiohttp,elastic-coders/aiohttp,flying-sheep/aiohttp,hellysmile/aiohttp,panda73111/aiohttp,elastic-coders/aiohttp,mind1master/aiohttp,mind1master/aiohttp,hellysmile/aiohttp,vaskalas/aiohttp,noodle-learns-programming/aiohttp,vaskalas/aiohttp,arthurdarcet/aiohttp,avanov/aiohttp,moden-py/aiohttp,singulared/aiohttp,alex-eri/aiohttp-1,singulared/aiohttp,pfreixes/aiohttp,rutsky/aiohttp,panda73111/aiohttp,decentfox/aiohttp,KeepSafe/aiohttp,elastic-coders/aiohttp,Srogozins/aiohttp,decentfox/aiohttp,KeepSafe/aiohttp,playpauseandstop/aiohttp,panda73111/aiohttp,alex-eri/aiohttp-1,mind1master/aiohttp,Eyepea/aiohttp,pathcl/aiohttp,pfreixes/aiohttp,danielnelson/aiohttp,jettify/aiohttp,rutsky/aiohttp,juliatem/aiohttp,AraHaanOrg/aiohttp,vaskalas/aiohttp,decentfox/aiohttp,z2v/aiohttp,KeepSafe/aiohttp,jettify/aiohttp,AraHaanOrg/aiohttp,esaezgil/aiohttp,rutsky/aiohttp,arthurdarcet/aiohttp,Insoleet/aiohttp,z2v/aiohttp,esaezgil/aiohttp,vedun/aiohttp,jashandeep-sohi/aiohttp,jashandeep-sohi/aiohttp,moden-py/aiohttp,arthurdarcet/aiohttp,jettify/aiohttp,sterwill/aiohttp,vasylbo/aiohttp,esaezgil/aiohttp,alex-eri/aiohttp-1,moden-py/aiohttp,singulared/aiohttp