Update for pyload-ng, replace Thrift client with REST client

[Sab44]

Fixes: https://github.com/pyload/pyload-android/issues/42

Note: the app will only work against a pyLoad server that has the changes from https://github.com/pyload/pyload/pull/4580 incorporated.

The existing custom File Chooser had to be removed to work with modern Android versions.

Important: This will restore basic functionality of the app. There will likely be bugs related to things no longer working on modern Android versions similar to the File Chooser. Any bug fixes should be done in follow-up PRs.

Tested:

• Login
• Overview / Queue / Collector
• Stop / Cancel / Resume downloads
• Server controls
• Start new download by uploading DLC

Currently untested:

• Captchas
• SSL