Add built-in storage support

[sergiofilhowz]

We want to add a built-in support to Storage service, that would encompass:

• Having a client library to allow file uploads (for browsers)
• Providing a built-in support in steps to quickly download files or create upload urls
• Providing a way to trigger steps when the file is uploaded

Examples: We can create a new file upload and set it to emit to a specific event when the file is uploaded.

Concept

const uploadUrl = await context.storage.createUploadUrl({
  path: '/path/to/folder/image.png',
  acceptMime: ['image/png']
  
  onUpload: {
    emit: 'image-uploaded'
  }
})

Concept UI

await motiaClient.storage.upload({
  url: uploadUrl,
  file: file, // this is a file instance selected from input
  onProgress: (percentage) => {
    console.log('upload percentage', percentage);
  }
});