Feature: allow to do a hostile takeover of an AI company (in singleplayer) (#10914)

With the removal of the share-system, you could no longer make an
AI disappear in a single player game. At least, not without going
into the console.

Codechange: Let the compile generate the master command table out of templated command traits.

This is using a non-intrusive type-traits like templated system, which
allows compile-time validation that the command table and the command
enum match up.