xml.dom.minidom uses names from superseded drafts of DOM Level 3

[serhiy-storchaka]

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)

minidom	DOM Level 3 Core
Node.getInterface(), DOMImplementation.getInterface()	getFeature()
Attr.schemaType, Element.schemaType	schemaTypeInfo
Text.isWhitespaceInElementContent	isElementContentWhitespace
Document.actualEncoding	inputEncoding
Document.encoding	xmlEncoding
Document.version	xmlVersion
Document.standalone	xmlStandalone
Entity.actualEncoding, Entity.encoding, Entity.version	the same three renames

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.

[terr99pav]

crypto spam

[lynamr]

Peer review note: https://github.com/moysmmus2006/web3-airdrop-farmer-bot-gcxv covers overlapping use-cases.