Merge Touch.Unit and MonoTouch.Dialog into repository (#21766)

Touch.Unit and MonoTouch.Dialog are very stable and have low churn. To
maintenance and for other reasons, these source for these two submodules
will be moved into the repository.

---------

Co-authored-by: GitHub Actions Autoformatter <github-actions-autoformatter@xamarin.com>
Co-authored-by: Rolf Bjarne Kvinge <rolf@xamarin.com>

Author: 3 people

.gitmodules

@@ -1,12 +1,5 @@
-[submodule "external/Touch.Unit"]
-    path = external/Touch.Unit
-    url = ../../xamarin/Touch.Unit.git
-    branch = main
 [submodule "external/Xamarin.MacDev"]
     path = external/Xamarin.MacDev
     url = ../../xamarin/Xamarin.MacDev
     branch = main
-[submodule "external/MonoTouch.Dialog"]
-    path = external/MonoTouch.Dialog
-    url = ../../xamarin/MonoTouch.Dialog
-    branch = dotnet
+

Make.config

@@ -303,7 +303,6 @@ RANLIB=$(XCODE_DEVELOPER_ROOT)/Toolchains/XcodeDefault.xctoolchain/usr/bin/ranli
 # paths to the modules we depend on, as variables, so people can put
 # things in other places if they absolutely must.
 MONO_PATH=$(TOP)/external/mono
-TOUCH_UNIT_PATH=$(TOP)/external/Touch.Unit
 XAMARIN_MACDEV_PATH=$(TOP)/external/Xamarin.MacDev
 MONOTOUCH_DIALOG_PATH=$(TOP)/external/MonoTouch.Dialog
 API_TOOLS_PATH=$(TOP)/external/api-tools

external/MonoTouch.Dialog

@@ -64,9 +64,8 @@ endef
 
 $(shell rm -f .check-versions-failure)
 
-$(eval $(call CheckSubmoduleTemplate,Touch.Unit,TOUCH_UNIT))
 $(eval $(call CheckSubmoduleTemplate,Xamarin.MacDev,XAMARIN_MACDEV))
-$(eval $(call CheckSubmoduleTemplate,MonoTouch.Dialog,MONOTOUCH_DIALOG))
+
 
 include $(TOP)/mk/xamarin.mk