--{ and --} not supported

[Jacbo1]

Is your feature request related to a problem? Please describe. mpv supports --{ and --} for grouping arguments with specific files but mpv.net does not.

Describe the solution you'd like Support --{ and --}

Additional context mpv.net treats them as trying to set properties.

[mpv.net] error setting property: { = yes
[mpv.net] property not found
[mpv.net] error setting property: } = yes
[mpv.net] property not found```