fix(xychart): include zero in scale domains by default

[williaster]

🐛 Bug Fix

This fixes a default behavior issue with XYChart scales, where their domains don't include zero by default if the scale allows. Including zero in the axis domain is generally best practice, and users can still opt out by setting x/yScaleConfig={{ zero: false }}.

Before
This AreaSeries has 3 y-values which are all equal and non-zero. It renders like this because the y-domain is [100, 100]. This was also reported in #1003

After
With the same data + chart config, the y-domain is now [0, 100].

Verified it works for negative values, and horizontal orientation.

🚀 Enhancements

• Adds a scaleCanBeZeroed typeguard util to @visx/scale (needed for typing these changes)
• exposes DataProvider's horizontal prop in XYChart (noticed a small TODO during this work)

@hshoff @kristw
cc @RIP21

[williaster]

noting that the domain was updated from number => ScaleInput (leftover from my comment here)

[coveralls]

Pull Request Test Coverage Report for Build 472873892

• 4 of 4 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.006%) to 61.202%

---

Totals
Change from base Build 466988844:	0.006%
Covered Lines:	1730
Relevant Lines:	2692

---

💛 - Coveralls