Code coverage improvements

[ghost]

This improves coverage in 3 small cases.

For the generic dictionary one, it turns out that the other version of the method was length checking already which made the check redundant as it wasn't possible to hit that line in general.

Part of #1823

[coveralls]

Pull Request Test Coverage Report for Build 4768494688

Warning: This coverage report may be inaccurate.

We've detected an issue with your CI configuration that might affect the accuracy of this pull request's coverage report.
To ensure accuracy in future PRs, please see these guidelines.
A quick fix for this PR: rebase it; your next report should be accurate.

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.06%) to 97.243%

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Totals
Change from base Build 4759863419:	0.06%
Covered Lines:	12849
Relevant Lines:	13085

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💛 - Coveralls

[jnyrup]

Did you intend to remove When_DataColumn_has_changes_but_is_excluded_in_all_tables_it_should_succeed as well?

[Fact]
public void When_DataColumn_has_changes_but_is_excluded_in_all_tables_it_should_succeed()
{
    // Arrange
    var dataSet1 = CreateDummyDataSet<TypedDataSetSubclass>();
    var dataSet2 = new TypedDataSetSubclass(dataSet1);

    var dataColumn1 = dataSet1.TypedDataTable1.DecimalColumn;
    var dataColumn2 = dataSet2.TypedDataTable1.DecimalColumn;

    dataColumn2.Unique = true;
    dataColumn2.Caption = "Test";

    // Act & Assert
    dataColumn1.Should().BeEquivalentTo(dataColumn2, options => options
        .ExcludingColumnInAllTables(dataColumn2.ColumnName));
}

[ghost]

Did you intend to remove When_DataColumn_has_changes_but_is_excluded_in_all_tables_it_should_succeed as well?

[Fact]
public void When_DataColumn_has_changes_but_is_excluded_in_all_tables_it_should_succeed()
{
    // Arrange
    var dataSet1 = CreateDummyDataSet<TypedDataSetSubclass>();
    var dataSet2 = new TypedDataSetSubclass(dataSet1);

    var dataColumn1 = dataSet1.TypedDataTable1.DecimalColumn;
    var dataColumn2 = dataSet2.TypedDataTable1.DecimalColumn;

    dataColumn2.Unique = true;
    dataColumn2.Caption = "Test";

    // Act & Assert
    dataColumn1.Should().BeEquivalentTo(dataColumn2, options => options
        .ExcludingColumnInAllTables(dataColumn2.ColumnName));
}

That wasn't intended, I restored it.