Bug when manipulation center outside the data q-range

[krzywon]

As noted in SasView/sasview#1346, all manipulations assume the center of averaging should be Q=(0,0). If this is outside the Q range of the data, the manipulation fails.

This could potentially be a two-part ticket. First, the manipulation should not fail when the averaging center is outside the data Q-range. Second, the averaging center should be modifiable and not fixed at the axis origins.

[butlerpd]

Working on cleanup in preparation for Contributor Camp XII:

@krzywon and @lucas-wilkins is this still true after the Ellis' refactoring? If not then we should close this issue.

[krzywon]

The work done by @ehewins is still in an open PR: #47. That said, the open PRs are awaiting a functionality review, which might tell us if this ticket has been addressed or not.