Add an ingame warning for missing map dependencies

### I am planning on implementing this myself

No

### Describe your request

Check if dependencies used in a map are not currently enabled, and display a warning ingame if this is the case. This could be displayed as a postcard or some other type of warning popup. A option in the popup to automatically enable all missing dependencies would be a nice addition to this feature.

Many maps (particularly older maps with inactive mappers) do not have their .yaml files configured properly, which means it is possible to play a map while unknowingly missing an intended dependency. Everest would fix this issue by warning players if the map is attempting to load properties from a dependency that is not enabled.

Along with being a general QOL feature, this would be useful for modded communities (such as the modded golden list) where it is common for players to be unaware of missing dependencies and unintentionally "break" a map. For the golden list, this leads to an issue where we are either forced to accept submissions with missing dependencies (which may make a map significantly easier), or we reject these submissions, which is unfair to the player who was likely unaware. If Everest displayed a warning ingame, then the issue of a lack of player knowledge would be solved.

### Additional context

_No response_