require("internet").request now returns a function object

The function object can be called to read from the stream, same usage as before
But the object also exposes the request handle userdata, to allow calling close for example:

```
local request = require("internet").request("http://www.google.com")
print(request()) -- same as before
request:close() -- clean up resources now, as opposed to waiting for gc
```

closes #2255

src/main/resources/assets/opencomputers/loot/openos/lib/internet.lua

@@ -11,10 +11,10 @@ function internet.request(url, data, headers)
   checkArg(2, data, "string", "table", "nil")
   checkArg(3, headers, "table", "nil")
 
-  local inet = component.internet
+  if not component.isAvailable("internet") then
-  if not inet then
     error("no primary internet card found", 2)
   end
+  local inet = component.internet
 
   local post
   if type(data) == "string" then
@@ -31,23 +31,35 @@ function internet.request(url, data, headers)
     error(reason, 2)
   end
 
-  return function()
+  return setmetatable(
-    while true do
+  {
-      local data, reason = request.read()
+    ["()"] = "function():string -- Tries to read data from the socket stream and return the read byte array.",
-      if not data then
+    close = setmetatable({},
-        request.close()
+    {
-        if reason then
+      __call = request.close,
-          error(reason, 2)
+      __tostring = function() return "function() -- closes the connection" end
-        else
+    })
-          return nil -- eof
+  },
+  {
+    __call = function()
+      while true do
+        local data, reason = request.read()
+        if not data then
+          request.close()
+          if reason then
+            error(reason, 2)
+          else
+            return nil -- eof
+          end
+        elseif #data > 0 then
+          return data
         end
-      elseif #data > 0 then
+        -- else: no data, block
-        return data
+        os.sleep(0)
       end
-      -- else: no data, block
+    end,
-      os.sleep(0)
+    __index = request,
-    end
+  })
-  end
 end
 
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