Since the theater commander runs once per campaign action, missions that
do not have aircraft available may be checked more than once a turn.
Without deduping requests this can lead to cases where the AI buys
dozens of tankers on turn 0.
Fixes https://github.com/dcs-liberation/dcs_liberation/issues/1470
The doctrine/task limits were capturing a reasonable average for the
era, but it did a bad job for cases like the Harrier vs the Hornet,
which perform similar missions but have drastically different max
ranges. It also forced us into limiting CAS missions (even those flown
by long range aircraft like the A-10) to 50nm since helicopters could
commonly be fragged to them.
This should allow us to design campaigns without needing airfields to be
a max of ~50-100nm apart.
This makes it so that the mission planning effects are applied only if
the package can be fulfilled. For example, breakthrough will be used
only if all the BAI missions were fulfilled, not if they will *attempt*
to be fulfilled.
