Migrate the ConPTY functional tests out of Windows (#4648)

## Summary of the Pull Request
This will allow us to run the ConPTY tests in CI.

## PR Checklist
* [x] Closes MSFT:24265197
* [X] I've discussed this with core contributors already.

## Validation Steps Performed
I've run the tests.

Please note: this code is unchanged (apart from `wil::ScopeExit` -> `wil::scope_exit`) from Windows. Now is not the time to comment on their perfectness.

OpenConsole.sln

@@ -294,6 +294,8 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Scripts", "Scripts", "{D3EF
 		build\scripts\Test-WindowsTerminalPackage.ps1 = build\scripts\Test-WindowsTerminalPackage.ps1
 	EndProjectSection
 EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "winconpty.Tests.Feature", "src\winconpty\ft_pty\winconpty.FeatureTests.vcxproj", "{024052DE-83FB-4653-AEA4-90790D29D5BD}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		AuditMode|Any CPU = AuditMode|Any CPU
@@ -1419,6 +1421,20 @@ Global
 		{A602A555-BAAC-46E1-A91D-3DAB0475C5A1}.Release|x64.Build.0 = Release|x64
 		{A602A555-BAAC-46E1-A91D-3DAB0475C5A1}.Release|x86.ActiveCfg = Release|Win32
 		{A602A555-BAAC-46E1-A91D-3DAB0475C5A1}.Release|x86.Build.0 = Release|Win32
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Debug|Any CPU.ActiveCfg = Debug|Win32
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Debug|ARM64.ActiveCfg = Debug|ARM64
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Debug|ARM64.Build.0 = Debug|ARM64
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Debug|x64.ActiveCfg = Debug|x64
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Debug|x64.Build.0 = Debug|x64
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Debug|x86.ActiveCfg = Debug|Win32
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Debug|x86.Build.0 = Debug|Win32
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Release|Any CPU.ActiveCfg = Release|Win32
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Release|ARM64.ActiveCfg = Release|ARM64
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Release|ARM64.Build.0 = Release|ARM64
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Release|x64.ActiveCfg = Release|x64
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Release|x64.Build.0 = Release|x64
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Release|x86.ActiveCfg = Release|Win32
+		{024052DE-83FB-4653-AEA4-90790D29D5BD}.Release|x86.Build.0 = Release|Win32
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -1493,6 +1509,7 @@ Global
 		{53DD5520-E64C-4C06-B472-7CE62CA539C9} = {04170EEF-983A-4195-BFEF-2321E5E38A1E}
 		{6B5A44ED-918D-4747-BFB1-2472A1FCA173} = {04170EEF-983A-4195-BFEF-2321E5E38A1E}
 		{D3EF7B96-CD5E-47C9-B9A9-136259563033} = {04170EEF-983A-4195-BFEF-2321E5E38A1E}
+		{024052DE-83FB-4653-AEA4-90790D29D5BD} = {E8F24881-5E37-4362-B191-A3BA0ED7F4EB}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {3140B1B7-C8EE-43D1-A772-D82A7061A271}