CA-339273: Mention source and destination Host/Pool in VM migrate action
CA-339273: Mention source and destination Host/Pool in VM migrate action

Also removed useless `this` calls and tidied code

Signed-off-by: Danilo Del Busso <766dc0f994b57f2d2e98930ecfa5ee8fb1091a62@citrix.com>

kc284/xenadmin,kc284/xenadmin,kc284/xenadmin,xenserver/xenadmin,xenserver/xenadmin,kc284/xenadmin,xenserver/xenadmin,kc284/xenadmin