add "Sheet Number" <does not equal this sheet> option for Sections Filters

[lionel.kai]

And probably a corresponding <equals this sheet> option, too.

When making key plans, we currently have to have a different Filter for every Sheet that has one. It would be nice if we could just have one "Sections not on Same Sheet" Filter that we could use to turn off all the other views. We'd still need to make a different plan for each sheet, but at least we wouldn't need to create and maintain Filters for every Sheet (and they could be kept in the View Template)

For example, we make a "Sections - not S-201, on Sheet" Filter for the S-201 Key Plan that catches all sections on a Sheet other than S-201. Then Visible is unchecked for that Filter. Then "Sections - not S-202, on Sheet" Filter for the S-202 Key Plan... repeat for every Sheet ad nauseum...

[lionel.kai]

Maybe I should have called it "Filter View by Sections visible on same Sheet" because this is essentially the View (& Sections) equivalent of Filter schedule by elements visible on same sheet

See also the same idea (for Referencing Sheet instead of Sheet Number): Filter sections on sheet (by Sheet Number = Referencing Sheet), but I'm not sure how useful that would be without also fixing the unpredictability of "Referencing Sheet".