Review NUnit1029

[atifaziz]

In PR #1023, updating the NUnit.Analyzers to version 3.8.0 introduced NUnit1029 warnings/errors:

A:\MoreLINQ\main\MoreLinq.Test\AggregateTest.cs(100,25,100,55): error NUnit1029: The TestCaseSource provides '1' parameter(s), but the Test method expects '2' parameter(s) (https://github.com/nunit/nunit.analyzers/tree/master/documentation/NUnit1029.md)
A:\MoreLINQ\main\MoreLinq.Test\ZipLongestTest.cs(46,31,46,47): error NUnit1029: The TestCaseSource provides '1' parameter(s), but the Test method expects '2' parameter(s) (https://github.com/nunit/nunit.analyzers/tree/master/documentation/NUnit1029.md)
A:\MoreLINQ\main\MoreLinq.Test\TrySingleTest.cs(58,25,58,61): error NUnit1029: The TestCaseSource provides '1' parameter(s), but the Test method expects '2' parameter(s) (https://github.com/nunit/nunit.analyzers/tree/master/documentation/NUnit1029.md)
A:\MoreLINQ\main\MoreLinq.Test\OrderedMergeTest.cs(65,31,65,47): error NUnit1029: The TestCaseSource provides '1' parameter(s), but the Test method expects '2' parameter(s) (https://github.com/nunit/nunit.analyzers/tree/master/documentation/NUnit1029.md)
A:\MoreLINQ\main\MoreLinq.Test\PrependTest.cs(61,25,61,50): error NUnit1029: The TestCaseSource provides '1' parameter(s), but the Test method expects '2' parameter(s) (https://github.com/nunit/nunit.analyzers/tree/master/documentation/NUnit1029.md)
A:\MoreLINQ\main\MoreLinq.Test\SkipUntilTest.cs(77,31,77,47): error NUnit1029: The TestCaseSource provides '1' parameter(s), but the Test method expects '2' parameter(s) (https://github.com/nunit/nunit.analyzers/tree/master/documentation/NUnit1029.md)

Since all tests pass regardless, the severity of NUnit1029 was demoted to suggestion:

MoreLINQ/MoreLinq.Test/.editorconfig

Lines 44 to 45 in 91d3996

	# Nunit1029: The number of parameters provided by the TestCaseSource does not match the number of parameters in the Test method
	dotnet_diagnostic.NUnit1029.severity = suggestion

It should be reviewed and ideally restored to a warning.