Perf: reduce metadata RSC payload (#50678)
### What
Currently when all the metadata rendered as JSX as server components, all the empty metadata which should be skipped as they're rendered as `null` in JSX, are still included in the RSC payload. This helps reduce the initial html size.
### How
Change the JSX components into function calls, and filter out the nullable component that won't be rendered, then they won't show up in the react tree and be serialized.
Before
```
self.__next_f.push([1, "5:[[[\"$\",\"meta\",null,{\"charSet\":\"utf-8\"}],null,null,null,null,null,null,null,null,null,null,[\"$\",\"meta\",null,{\"name\":\"viewport\",\"content\":\"width=device-width, initial-scale=1\"}],null,null,null,null,null,null,null,null,null,null,[]],[null,null,null,null],null,null,[null,null,null,null,null],null,null,null,null,null]\n"])
```
After
```
self.__next_f.push([1, "5:[[[\"$\",\"meta\",\"charset\",{\"charSet\":\"utf-8\"}],[\"$\",\"meta\",\"viewport:width=device-width, initial-scale=1\",{\"name\":\"viewport\",\"content\":\"width=device-width, initial-scale=1\"}]]]\n"])
```
Closes NEXT-1232
