Popup when user do not have a corresponding preview Edge Browser
[x] Add a new feature called Evergreen Preview (selects from least stable to most stable), and with the corresponding checkboxes. The selection boxes and checkboxes should update ReleaseChannels and ChannelSearchKind Reg Key.
[x] Checkboxes should be greyed out if not selected
[ ] Add popup to notify users that they do not have a specific preview Edge Browser installed if they check on a preview checkbox (if user checks Canary, a popup should show if the user has not already have Edge Canary installed)
Ideal end result of UI
Popup when user do not have a corresponding preview Edge Browser
This enhancement covers both #72, #73