Constrain zoom levels

[kwvanderlinde]

Identify the Bug or Feature request

Fixes #2264

Description of the Change

The zoom level has been clamped to a more reasonable range.

• Minimum level: -175, or 0.0003%
• Maximum level: 175, or 31,367,597%

These numbers aren't very meaningful aside from avoiding the extremes while still giving lots of freedom. There's a bit of room on each side yet if we want to push it.

The AdjustGridPanel and AdvancedAdjustGridPanel were removed as they were unused and put extra requirements on Scale.

Possible Drawbacks

None

Documentation Notes

N/A

Release Notes

• Fixed a bug where the viewport would suddenlty jump when zooming in really far.

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This change is 

[cwisniew]

Approved although I wonder about your definition of "reasonable" for the range :)