Show loading screens on load

[Richard-L]

As we'd discussed, theoretically still missing as of yet. Had ideally been consistent with later TR2X (and even a TR3X 🤞).

To be decided how long the images should show. On a new level start, it seems desirable to keep the 5 sec length. On a regular load, would these only show briefly and fade into the level?

[aredfan]

TR3 PC loading from the main menu and in-game, for reference.

Video.mp4

[rr-]

This is polarizing so let's make it into an enum option.