[Server Transfers] Add API Applications endpoint

[alexevladgabriel]

Howdy, glad to see you there reading this,

This PR, add the API endpoint to /api/application/servers, so you can use it, alongside custom scripts to migrate entire nodes from one to another, until I add support to node migrations from one node to another.

@DenDanskeMine
Why is it useful?
This would help automate hardware upgrades or server migrations when customers request to move to a better node. Right now, this is a slow manual process that can’t be automated.

Closes: #5358