add option to download unity templates

[unitycoder]

since they are probably accessible without login

• find out what urls are used for downloading templates
• add option to downloading/using unity template when creating new project

[hifron]

unity suggestion for templates is make a project, copy it and rename

some packages templates like for 2D projects and then manually uninstall packages via Unity Editor UI, download assets and install some packages, configure external editor(and built settings in future without asmdef but with .NET build(and someday also with XML .NET csprojectx build)) and AI usage, this is out of Unity.com NASDAQ thought... because programmers are hot for not healthy templates disaster...