chore: Move test projects to a solution folder

src/Recyclarr.sln

@@ -35,6 +35,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Recyclarr.Gui", "Recyclarr.
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Recyclarr.Common.TestLibrary", "Recyclarr.Common.TestLibrary\Recyclarr.Common.TestLibrary.csproj", "{A92321B5-2796-467B-B5A5-2BFC41167A25}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Tests", "Tests", "{18E17C53-F600-40AE-82C1-3CD1E547C307}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -96,4 +98,14 @@ Global
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {AFBE3E4F-DA4D-4EBD-8700-C3C42B59D6AB}
 	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{77D1C695-94D4-46A9-8F12-41E54AF97750} = {18E17C53-F600-40AE-82C1-3CD1E547C307}
+		{217D5972-4BB7-4343-9043-C30BD9A1811E} = {18E17C53-F600-40AE-82C1-3CD1E547C307}
+		{A92321B5-2796-467B-B5A5-2BFC41167A25} = {18E17C53-F600-40AE-82C1-3CD1E547C307}
+		{0720939D-1CA6-43D7-BBED-F8F894C4F562} = {18E17C53-F600-40AE-82C1-3CD1E547C307}
+		{49F28A82-468F-4C48-9A59-D41B8FE26D6E} = {18E17C53-F600-40AE-82C1-3CD1E547C307}
+		{BF105B2F-8E13-48AD-BF72-DF7EFEB018B6} = {18E17C53-F600-40AE-82C1-3CD1E547C307}
+		{33226068-65E3-4890-8671-59A56BA3F6F0} = {18E17C53-F600-40AE-82C1-3CD1E547C307}
+		{A4EC7E0D-C591-4874-B9AC-EB12A96F3E83} = {18E17C53-F600-40AE-82C1-3CD1E547C307}
+	EndGlobalSection
 EndGlobal