fix compatibility with no-fs enviroments (workerd)

[carafelix]

• remove the import of the upload function for runtimes that do not have a file system
• add test's for each of the functionalities.

What's the cleanest way to tree shake the upload function? Since the upload function depends on fs an Deno.open respectively

• opt-out: the upload function it's in the package by default, and in envs like workerds you would "import telegraph from grammy/posts/workerds" (or, /nofs)
• opt-in: the base package would come for everyone the same, an additional upload function could be imported from "grammy/posts/upload", for example. This way the upload function could be it's own package.

Is there any other way around it?

Edit: I did a small gist using inputFile, for obvious reasons this is not ok, it's specially bad, not because it would first upload it to telegram and then fetch the getFile and the use that link for uploading it to telegraph, it is because the user would the photo, see it delete, and then receive the post).

I'm leaning towards distributing it with no upload function and having a separate package for the upload, like mentioned in the opt-in option. That would need a rework of the telegraph bindings package