Remove: [Script] CONFIG_RANDOM from AddSetting flags (#11942)

It had a very weird interaction, and was only ever used by a single
AI.

Codechange: Make SpriteType, CargoSortType, SourceType and ScriptType enum classes. (#10663)

This avoids a (soft) namespace conflict between the four ST_* enums.

Change: rebrand 1.12.0 to 12.0

One question that keeps popping up: "when do we release 2.0?".
NewGRF will force that at least 1.16 will be 2.0, but to not wait
for this, let's drop the "1." and be for ever done with that
conversation.

We are following in the footstep of giants here.