Restore "Merge pull request #8087 from cvium/generic_subtitleparser"

After tagging v10.8.3, this can be restored to how it was and corrected
as required in a separate PR.

This reverts commit 494ed7e4d2.

MediaBrowser.MediaEncoding/Subtitles/SsaParser.cs

@@ -1,19 +0,0 @@
-using Microsoft.Extensions.Logging;
-using Nikse.SubtitleEdit.Core.SubtitleFormats;
-
-namespace MediaBrowser.MediaEncoding.Subtitles
-{
-    /// <summary>
-    /// SubStation Alpha subtitle parser.
-    /// </summary>
-    public class SsaParser : SubtitleEditParser<SubStationAlpha>
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="SsaParser"/> class.
-        /// </summary>
-        /// <param name="logger">The logger.</param>
-        public SsaParser(ILogger logger) : base(logger)
-        {
-        }
-    }
-}