* Update `$POF file Techroom:` Usage
Currently `$POF file Techroom:` is only used in the weapons loadout screen (despite having techroom in the name). This PR expands the use of the `$POF file Techroom:` to shiploadout select and the actual techroom.
If it is desired I can put it behind a game settings flag, but IMO it would make the most sense for modders to have this just work as the actual name implies.
* clean up code with feedback
* typo fix in comment