add error handling for missing client

Author: Nsidorenco

lua/neotest-vstest/init.lua

@@ -517,6 +517,15 @@ local function create_adapter(config)
         if client then
           local tests = projects[client] or {}
           projects[client] = vim.list_extend(tests, { position.id })
+        else
+          vim.notify_once(
+            string.format(
+              "neotest-vstest: could not find adapter client for test '%s' in project '%s'",
+              position.name,
+              vim.inspect(position.project)
+            ),
+            vim.log.levels.WARN
+          )
         end
       end
     end