`tns preview` does not handle custom binary files

Is your feature request related to a problem? Please describe.

The tns preview command syncs files based on their file extension. If the file is binary it should be sent as base64 encoded file. Currently the check is based on a third party dependency istextorbinary
https://github.com/NativeScript/nativescript-cli/blob/8722364da49c9950e65d79014e66d3a17a59d0ce/lib/services/livesync/playground/preview-app-files-service.ts#L65

This lib only supports a limited set of binary extensions
https://github.com/bevry/binaryextensions/blob/master/source/index.json

Describe the solution you'd like

Add a parameter to the command to allow adding additional extensions that must be handled as binary.

從 lib/services/livesync/playground/preview-app-files-service.ts 第 65 行附近的檔案類型檢查開始，然後追蹤 tns preview 命令參數的定義方式。新增一種指定必須視為二進位檔案處理的額外副檔名的方法，並確認這些檔案會以 base64 編碼的內容進行同步。