Blender Git Loki

UI: Avoid unnecessary redraws of unrelated editors on space changes

When adding a notifier, `reference` data can be passed. The notifier system
uses this to filter out listeners, for example if data of a scene changes,
windows showing a different scene won't get the notifiers sent to their
listeners.

For the `NC_SPACE` notifiers, a number of places also passed the space as
`reference`, but that wasn't used at all. The notifier would still be sent to
all listeners in all windows (and the listeners didn't use it either). Causing
some unnecessary updates (e.g. see ed2c4825d3e2344).
With this commit, passing a space will make sure the notifier is only sent to
that exact space. Some code seems to already have expected that to be the case.

However there were some cases that passed the space as `reference` without
reason, which would break with this commit (meaning they wouldn't redraw or
update correctly).
Corrected these so they don't pass the space anymore.