Add support for HTMLElement.removeAttributeNode.

[TrevorKarjanis]

Purpose

HTMLElement.attributes returns an attributes wrapper that clones stored attribute nodes. Iterating over the attributes and passing a cloned attribute to HTMLElement.removeAttributeNode results in an exception that fails tests.

Approach

Add support for HTMLElement.removeAttributeNode that reuses the removeAttributeCore implementation and supports namespaced attributes. Base attribute node and removeAttributeNode usage on the DOM living standard. Attempt to remove stored nodes, but continue not to the throw. Pass the attribute from the native attributes list to the native removeAttributeNode, and allow the call to refreshAttributesWrapper to remove it or the clone from the wrapper. Add string representation and method unit tests, and base them on the existing tests for removeAttribute. Native function argument DOM tests don't apply. Make a concerted effort to match existing code style.

References

• Error with FAST button testcafe#6785
• Removing xlink:href attribute node from <use> element throws error #1901

Pre-Merge TODO

• Write tests for your proposed changes
• Make sure that existing tests do not fail

[miherlosev]

Hi @TrevorKarjanis

Thank you for your contribution to TestCafe. We will review this PR.