Add test for decoding of nested arrays of enums (CoreOffice#126)

Add `NestedChoiceArrayTest` based on the code shared in CoreOffice#122.

Author: bwetherfield

XMLCoder.xcodeproj/project.pbxproj

@@ -30,6 +30,7 @@
 		D11E094A234924C500C24DCB /* ValueBox.swift in Sources */ = {isa = PBXBuildFile; fileRef = D11E0949234924C500C24DCB /* ValueBox.swift */; };
 		D18FBFB82348FAE500FA4F65 /* QuoteDecodingTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = D18FBFB72348FAE500FA4F65 /* QuoteDecodingTest.swift */; };
 		07E441BA2340F14B00890F46 /* EmptyElementEmptyStringTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 07E441B92340F14B00890F46 /* EmptyElementEmptyStringTests.swift */; };
+		B5EA3BB6230F237800D8D69B /* NestedChoiceArrayTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5EA3BB4230F235C00D8D69B /* NestedChoiceArrayTest.swift */; };
 		B5F74472233F74E400BBDB15 /* RootLevelAttributeTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5F74471233F74E400BBDB15 /* RootLevelAttributeTest.swift */; };
 		OBJ_148 /* BoolBox.swift in Sources */ = {isa = PBXBuildFile; fileRef = OBJ_12 /* BoolBox.swift */; };
 		OBJ_149 /* Box.swift in Sources */ = {isa = PBXBuildFile; fileRef = OBJ_13 /* Box.swift */; };
@@ -171,6 +172,7 @@
 		D11E0949234924C500C24DCB /* ValueBox.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ValueBox.swift; sourceTree = "<group>"; };
 		D18FBFB72348FAE500FA4F65 /* QuoteDecodingTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = QuoteDecodingTest.swift; sourceTree = "<group>"; };
 		07E441B92340F14B00890F46 /* EmptyElementEmptyStringTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EmptyElementEmptyStringTests.swift; sourceTree = "<group>"; };
+		B5EA3BB4230F235C00D8D69B /* NestedChoiceArrayTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NestedChoiceArrayTest.swift; sourceTree = "<group>"; };
 		B5F74471233F74E400BBDB15 /* RootLevelAttributeTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RootLevelAttributeTest.swift; sourceTree = "<group>"; };
 		OBJ_100 /* DecimalTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DecimalTests.swift; sourceTree = "<group>"; };
 		OBJ_101 /* EmptyTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EmptyTests.swift; sourceTree = "<group>"; };