Editor modes (start / play / pause)

[itsdouges]

Currently the editor has no concept of start / stop / playing the currently opened component. This feature would allow you to by default have a scene be "paused" (no frames would tick) until you "play" the scene. The frame loop for the scene would still tick forward but the frame loop for the user land features would be controlled. This is nuanced and there are varying ways we can accomplish this. This issue would document paths forward and then implement it.

Speak to @krispya for insights.