xml.dom.minidom uses names from superseded drafts of DOM Level 3

Several public attributes and methods of xml.dom.minidom come from working drafts of DOM Level 3, and were renamed before the Recommendation was published in 2004. The code says so itself:

# DOM Level 3 attributes, based on the 22 Oct 2002 draft
# DOM Level 3 (WD 9 April 2002)

Document.errorHandler is from the same drafts; in the Recommendation it became a parameter of domConfig.

None of these names are documented, so nothing tells a user that they are neither DOM Level 1/2 (which xml.dom documents) nor DOM Level 3 (which minidom does not claim, see gh-50348).

Adding the specified names and keeping the old ones as aliases breaks nothing, and lets the documented API match the specification.

Linked PRs

• gh-156696

从 xml.dom.minidom 入口点开始，检查 issue 中列出的公共属性和方法，以及它们的 DOM Level 3 注释。将每个当前名称与 Recommendation 中指定的名称进行比较；当指定的名称可作为别名使用且不会破坏旧名称，并且现有测试中有适当的覆盖时，即表示完成。