Remove redundant ToQuantity methods

[AKTheKnight]

This PR removes the ToQuantity methods that accept an int as a parameter and leaves the ones that accept a long.

As all the methods call the same method linked below, that only accepts a long, we already box everything down to a long to begin with:

Humanizer/src/Humanizer/ToQuantityExtensions.cs

Line 107 in d5b3cf3

private static string ToQuantity(this string input, long quantity, ShowQuantityAs showQuantityAs = ShowQuantityAs.Numeric, string format = null, IFormatProvider formatProvider = null)

Also remove unneeded AssertEquals that box ints to longs

[clairernovotny]

While this is code compatible, it is a binary breaking change. It can go in for the next major release.

[AKTheKnight]

Oops, didn't mean to close this PR.

[SimonCropp]

@AKTheKnight i raised and merged a new PR. to save you the merge conflicts. And i credited you on the commit

will close this one