feat: basic initial implementation of spotify client link validator and song submission form refs: NOISSUE

song_of_the_day/SongValidators/UriBasedSongValidatorBase.cs

@@ -0,0 +1,12 @@
+using System.Text.RegularExpressions;
+
+public abstract class UriBasedSongValidatorBase : SongValidatorBase
+{
+    public abstract string UriValidatorRegex { get; }
+
+    public override bool CanValidateUri(Uri songUri)
+    {
+        var regexp = new Regex(UriValidatorRegex, RegexOptions.IgnoreCase);
+        return regexp.Match(songUri.ToString()).Success;
+    }
+}