HaveCount with special cases for 0 or 1

[jnyrup]

This is really just a nice to have.

list.Count().Should().Be(0);
list.Count().Should().Be(1);

are correctly simplified into:

list.Should().HaveCount(0);
list.Should().HaveCount(1);

It would be nice, if they could be simplified directly into the ContainSingle and BeEmpty instead.

list.Should().ContainSingle();
list.Should().BeEmpty();

[Meir017]

right now it takes to code-fixes to get there since list.Should().HaveCount(0); triggers CollectionShouldBeEmptyAnalyzer that suggests list.Should().BeEmpty();.

it will be available next release