Face Nearest only works with individual projection, so always set the
`SCE_SNAP_PROJECT` flag in this case.
Also gray out the `Project Individual Elements` option in the UI if
`Face Nearest` is enabled.
And change the description to indicate that `Project Individual Elements`
is always enabled with the `Face Nearest` option.
(I feel a better design for this option needs to be considered).
6778460e53