change attribute value access from ent.comp.attr.value to ent.comp.attr directly

app devs typically want the value directly, both for getting and modifying, and rarely (so far never?) need the actual attribute object. this changes the shorthand for attribute access in Component to give the value directly.

the networking internals use the attribute object but that remains here as before, it still has the still useful .value getter.

we'll test this still also against the custom pong client, i can merge then if all seems good still.

NOTE: attribute validation would be good to add.