fix(jukebox): fix mpv command and template parsing (#4162)

* test(mpv): add unit tests for MPV command generation and execution

Signed-off-by: Deluan <deluan@navidrome.org>

* fix(mpv): improve command template parsing

Signed-off-by: Deluan <deluan@navidrome.org>

* fix(mpv): update mock script to output arguments to stdout instead of a file

Signed-off-by: Deluan <deluan@navidrome.org>

* test(mpv): add test suite for MPV command functionality

Signed-off-by: Deluan <deluan@navidrome.org>

* fix(mpv): improve MPV command template parsing to handle quoted arguments

Signed-off-by: Deluan <deluan@navidrome.org>

* fix(mpv): simplify MPV command check by removing unnecessary string containment

Signed-off-by: Deluan <deluan@navidrome.org>

* fix(mpv): add error handling for empty command arguments and malformed templates

Signed-off-by: Deluan <deluan@navidrome.org>

---------

Signed-off-by: Deluan <deluan@navidrome.org>

go.mod

@@ -34,6 +34,7 @@ require (
 	github.com/hashicorp/go-multierror v1.1.1
 	github.com/jellydator/ttlcache/v3 v3.3.0
 	github.com/kardianos/service v1.2.2
+	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/kr/pretty v0.3.1
 	github.com/lestrrat-go/jwx/v2 v2.1.6
 	github.com/matoous/go-nanoid/v2 v2.1.0
@@ -85,7 +86,6 @@ require (
 	github.com/gorilla/css v1.0.1 // indirect
 	github.com/hashicorp/errwrap v1.1.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
-	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 // indirect
 	github.com/klauspost/cpuid/v2 v2.2.10 // indirect
 	github.com/kr/text v0.2.0 // indirect
 	github.com/lann/builder v0.0.0-20180802200727-47ae307949d0 // indirect