add option to download unity templates #147

since they are probably accessible without login

• find out what urls are used for downloading templates
• add option to disable online templates (so that it doesnt start fetching online content)
• show which templates are already downloaded
• check if hub has already downloaded some templates? *saved in C:\Users\%USERNAME%\AppData\Roaming\UnityHub\Templates
• cache downloaded template files into some folder (if hub is installed, could use same folder that they use)
• unpack template into new project *Need to update packages.json also? it was missing some packages after imported template.. * can actually do this, unity.exe -createproject "myfolder.." -cloneFromTemplate "...Roaming\UnityHub\Templates\com.unity.template.mr-multiplayer-1.0.3.tgz"
• also some sample assets are not automatically pulled in (from xr interaction toolkit for example?) OR some 3rd party scripts missing?
• filter templates by selected unity version
• show necessary details for selected template (from graphql data) in mouse over or when selected
• show if update is available for already downloaded template *not sure how to check that?
• add context menu to explore template cache folder
• cache templates fetch per unity version (per session?)
• disable init script when using template?