resolve video external player play

[yixinin]

player url missing domain.

example:

• potplayer
  • current result: potplayer:///api/v3/file/download/xxx
  • expected：potplayer://https://a.b.c/api/v3/file/download/xxx

there is missing [protocol]//[domain]

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[yixinin]

Cloudreve #1336 #1732 https://github.com/cloudreve/Cloudreve/issues/1336 https://github.com/cloudreve/Cloudreve/issues/1732