Add LOC entries for Coop Missions.

[Yuchenjimmy]

Currently several coop missions doesn't have any LOC entries, I would like to add them in.

[Yuchenjimmy]

Any suggestion for the naming style?
e.g. FAF_Coop_Fort_Clarke_Assault_M4P2Description v.s. FAF_Coop_Fort_Clarke_Assault_001

[speed2CZ]

Same as the cue name, like here https://github.com/FAForever/faf-coop-maps/blob/master/FAF_Coop_Operation_Trident/FAF_Coop_Operation_Trident_strings.lua

[Yuchenjimmy]

Ok, NP.

[Yuchenjimmy]

Since LOC entries would interfere mission order, I decided to add a function auto generating LOC entries for FAF Coops, instead of directly editing scenario file.