Unit test for the remove_query_arg method

[borgesbruno]

Continuing my noble purpose to increase the code coverage =D, I wrote some tests for the remove_query_arg, this one removes query from the current URI using all query keys (Array or string) specified on the first param.

[boonebgorges]

Thanks, @borgesbruno! It is indeed a noble purpose :)

A couple of minor notes about formatting and convention:

• I'm going to move these tests to their own file
• The argument format for the dataProvider seems backward to me, so I'm going to change it to match the syntax of the function more closely
• You've provided error messages, but they're not really descriptive. We generally don't give error messages like this unless they're useful enough to help debug without opening the test files
• It seems to me that the core functionality of remove_query_arg() can be more succinctly tested by passing in an explicit URL. It's worthwhile to test that the current URL is used as a fallback, but I think it should happen in a separate test
• No need for a @ticket annotation if the tests being introduced don't demonstrate a bug or a bugfix

[boonebgorges]

In 37631:

Add tests for remove_query_arg().

Props borgesbruno.
Fixes #37008.

[borgesbruno]

Tks for your feedback @boonebgorges, I've seen your commit, it is pretty good.