switch to vcpkg+cmake, add debian build to workflows

using lionkor's template (MIT licensed)

This is a combination of 64 commits.

cmake/Vcpkg.cmake

@@ -0,0 +1,17 @@
+if(NOT DEFINED CMAKE_TOOLCHAIN_FILE)
+    if(NOT EXISTS ${CMAKE_SOURCE_DIR}/vcpkg/scripts/buildsystems/vcpkg.cmake)
+        find_package(Git)
+        if(Git_FOUND)
+            execute_process(COMMAND ${GIT_EXECUTABLE} submodule update --init --recursive vcpkg
+                            WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+                            RESULT_VARIABLE GIT_SUBMOD_RESULT)
+            if(NOT GIT_SUBMOD_RESULT EQUAL "0")
+                message(SEND_ERROR "Checking out vcpkg in source tree failed with ${GIT_SUBMOD_RESULT}.")
+            endif()
+        else()
+            message(FATAL_ERROR "Could not find git or vcpkg.cmake. Please either, install git and re-run cmake (or run `git submodule update --init --recursive`), or install vcpkg and add `-DCMAKE_TOOLCHAIN_FILE=<path-to-vcpkg>/scripts/buildsystems/vcpkg.cmake` to your cmake invocation. Please try again after making those changes.")
+        endif()
+    endif()
+    set(CMAKE_TOOLCHAIN_FILE ${CMAKE_SOURCE_DIR}/vcpkg/scripts/buildsystems/vcpkg.cmake)
+endif()
+