Recent demo updates (up to v8)

On top of the usual work, this has been an interesting week (and it's not even over yet). Many fairly basic issues were found - and fixed.

Hopefully if anything in the game was unclear or confusing before - the recent updates should address that.

Main issues fixed in v8:

• Mission selection will now show directly below the unfinished missions how many points are needed to unlock more missions. This should help address any confusion regarding the scope of the demo (12 missions across 2 locations).

• Each mission in mission selection should now also show in various places (depending on relevance) how many points completing the mission would add to the total. This should motivate finishing the tutorial even if it seems unnecessary, especially since it's almost certainly going to be useful for understanding how parts of this game work.

• Removed local interaction prompt when unable to interact, specifically to avoid confusion in the knocking selection of the enemy tutorial as to what is expected to proceed.

Main issues fixed in v7:

• Added a new section to the NPCs tutorial to teach knocking

• Added more sound visualization effects (for door impacts and knocking)

• Improved character physics, especially corner impact handling (should remove some ugly jittering)

• Added a visualizing triangle in the preview map making the starting position easier to find

• Improved the visibility of the knock icon

• Fixed an issue with the tool shooting light rays through walls while holding a door