Rework Flag Display Mode

[Cernel]

Rework Flag Display Mode

1. Setting changes:

Currently, the Flag Display Mode works this way:

View/Flag Display Mode/Show Unit Flags (Y/N)
View/Flag Display Mode/Small
View/Flag Display Mode/Large

I suggest to change it working this way:

View/Flag Display Mode/None
View/Flag Display Mode/Small
View/Flag Display Mode/Large

For example, currently, if you want to enable the display and set it on large, it takes two clicks. By my suggestion, any changes would take 1 click only.

2. Per game dependant:

I suggest to make such settings game dependant, not general, just like the zoom settings already are.
Meaning that if you enable unit flags for a game, it stays enabled for that game only, not generally.

3. Opt out option for mapmakers:

I also suggest having the option of setting, in "map.properties" to not have "Small", "Large" or both, in case the mapmaker believes this feature being unworthwhile for the specific map. If both options are opted out, then "Flag Display Mode" should not be available, altogether, for that map.

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I believe the above changes are propedeutical to further improvements of this functionality, also in the sense of having it possibly used as a not optional feature, to have flags always present in all or some units, alternatively to the current abit of just adding them in the unit images themselves (like Total World War, 270BC, etc.).
Such further improvements may consist in an option for not being able to switch flags out, being able to choose the flag image for the units specifically, being able to set where the flag is located, etc.. If there is interest, this can, then, be discussed and tested further, but, for now, this feature request is limited to the 3 points above.