obs-ffmpeg: Add missing translations

The name of the obs_output_t won't appear in usual operation but some
output types have the translation and others do not. Let's translate
them.
Also translate `FilePath` property name.

plugins/obs-ffmpeg/data/locale/en-US.ini

@@ -1,4 +1,8 @@
 FFmpegOutput="FFmpeg Output"
+FFmpegMuxer="FFmpeg Muxer"
+FFmpegHlsMuxer="FFmpeg HLS Muxer"
+FFmpegMpegts="FFmpeg MPEG-TS"
+FFmpegMpegtsMuxer="FFmpeg MPEG-TS Muxer"
 FFmpegAAC="FFmpeg AAC"
 FFmpegOpus="FFmpeg Opus"
 FFmpegALAC="FFmpeg ALAC (24-bit)"
@@ -17,6 +21,7 @@ RateControl="Rate Control"
 KeyframeIntervalSec="Keyframe Interval (0=auto)"
 Lossless="Lossless"
 Level="Level"
+FilePath="File Path"
 
 AMFOpts="AMF/FFmpeg Options"
 AMFOpts.ToolTip="Use to specify custom AMF or FFmpeg options. For example, \"level=5.2 profile=main\". Check the AMF encoder docs for more details."