Fix properties types

[SYNchroACK]

• Rename properties types based on the naming pattern
• Add missing _type field

[rpiazza]

@chisholm - is this worth merging?

[chisholm]

In principle, I am okay with what the changes are doing. But this doesn't appear to change type names in enough places. For example, see imports in:

cti-python-stix2/stix2/v21/__init__.py

Lines 26 to 35 in 6dd83fa

	from .observables import (
	URL, AlternateDataStream, ArchiveExt, Artifact, AutonomousSystem,
	CustomObservable, Directory, DomainName, EmailAddress, EmailMessage,
	EmailMIMEComponent, File, HTTPRequestExt, ICMPExt, IPv4Address,
	IPv6Address, MACAddress, Mutex, NetworkTraffic, NTFSExt, PDFExt, Process,
	RasterImageExt, SocketExt, Software, TCPExt, UNIXAccountExt, UserAccount,
	WindowsPEBinaryExt, WindowsPEOptionalHeaderType, WindowsPESection,
	WindowsProcessExt, WindowsRegistryKey, WindowsRegistryValueType,
	WindowsServiceExt, X509Certificate, X509V3ExtensionsType,
	)

This change breaks some of those imports. Perhaps an IDE should be used to do the refactor, to ensure the names are changed in all places they are used.

[CLAassistant]

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