Split the logic that handled updates into an :upgrade action
Split the logic that handled updates into an :upgrade action

The previous install logic had some flaws:

1) It relied on pkgutils to determine if xcode was installed and that doesn't seem to be entirely reliable. I copied over the plist logic from the macos cookbook, which seems much more reliable
2) The previous :install action was actually an :upgrade action on Macs which was VERY slow since it required reaching out to Apple's update servers. This corrects that behavior with a new :upgrade action that applies to macOS systems

Signed-off-by: Tim Smith <764ef62106582a09ed09dfa0b6bff7c05fd7d1e4@chef.io>

MsysTechnologiesllc/chef,MsysTechnologiesllc/chef,mwrock/chef,mattray/chef,nvwls/chef,mattray/chef,jaymzh/chef,nvwls/chef,higanworks/chef,gene1wood/chef,nvwls/chef,mattray/chef,nvwls/chef,tas50/chef-1,tas50/chef-1,jaymzh/chef,jaymzh/chef,tas50/chef-1,MsysTechnologiesllc/chef,jaymzh/chef,chef/chef,higanworks/chef,MsysTechnologiesllc/chef,mwrock/chef,nvwls/chef,higanworks/chef,gene1wood/chef,gene1wood/chef,higanworks/chef,chef/chef,gene1wood/chef,mwrock/chef,mattray/chef,higanworks/chef,nvwls/chef,tas50/chef-1,chef/chef,mwrock/chef,chef/chef,mattray/chef