add request permissions page

[patricklx]

fixes #2516

Description

this adds a link to a request permission page for ember inspector. It can only be requested during an user action, like a click. The page will open in a separate window, this is one of the possibilities to request permissions. It cannot be done directly from the extension page in devtools.

Screenshots

[RobbieTheWagner]

@patricklx can you please explain in more detail what this PR is for? Is it just a shortcut to request permissions? Can we not add the request permissions stuff to the icon in the toolbar of Chrome?

[patricklx]

@RobbieTheWagner in the toolbar you can already click on the ember icon and select which permissions to give to local website. So this is just a shortcut and a link to the page will be presented on the ember inspector error page.