kmail/ kde-pim: install via NixOS option instead

Installing the kde-pim sutie is quite complex. Thus, there's a
`programs.kde-pim` in NixOS now to keep track of all necessarry
packages.

Removing the attempted list of necessary packages from explicit NixOS
and home packages instead.

home/modules/packages.nix

@@ -198,13 +198,6 @@ let
       okular
       gwenview
       yakuake
-      kmail
-      kontact
-      korganizer
-      akonadi-mime # for KOrganizer
-      kmail-account-wizard
-      akonadi-import-wizard
-      kaddressbook
       kdeconnect
       dolphin
       spectacle