Re-add MatchData and variants

src/spectator/matchers/failed_match_data.cr

@@ -0,0 +1,17 @@
+require "./labeled_value"
+require "./match_data"
+
+module Spectator::Matchers
+  struct FailedMatchData < MatchData
+    def matched?
+      false
+    end
+
+    getter failure_message : String
+
+    getter values : Array(LabeledValue)
+
+    def initialize(@failure_message, @values = [] of LabeledValue)
+    end
+  end
+end

src/spectator/matchers/match_data.cr

@@ -0,0 +1,5 @@
+module Spectator::Matchers
+  abstract struct MatchData
+    abstract def matched? : Bool
+  end
+end

src/spectator/matchers/successful_match_data.cr

@@ -0,0 +1,9 @@
+require "./match_data"
+
+module Spectator::Matchers
+  struct SuccessfulMatchData < MatchData
+    def matched?
+      true
+    end
+  end
+end