Split "Establish Embassy".

Split "Establish Embassy".

Stop relying on the Spy unit type flag to decide if "Establish Embassy"
consumes the actor unit. Split "Establish Embassy" in an actor unit
consuming and in a non actor unit consuming version.

This makes it possible to create a ruleset where all actor units, including
those with the Spy utype flag, are consumed during embassy establishing. It
makes a ruleset where no actor units, including those without the Spy utype
flag, are consumed during embassy establishing possible. It also makes more
complex rules, like "establishing an embassy during war consumes the actor
unit", possible.

See hrm Feature #656188

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@35369 a0f10bec-cc02-0410-94fc-a9cfff90b4cd