Remove BinaryFormatter for property bag serialization

[JeremyKuhne]

Our IPropertyBag implementations rely on BinaryFormatter to serialize to and from a Hashtable/IStream. AxHost.PropertyBagStream and Control.ActiveXImpl.PropertyBagStream are the implementations.

In most of the places we've removed BinaryFormatter we've relied on TypeConverter to convert to/from either string or byte[]. The idea here is to serialize to/from JSON (using System.Text.Json) with this same dependency on TypeConverter. If there is no such TypeConverter for a given type, it would be ignored. Working around this breaking change would require writing and registering a TypeConverter that supports one of these two formats.

#7986 is a related change.

cc: @GrabYourPitchforks

[elachlan]

Should we convert from Hashtable to Dictionary<TKey,TValue> as apart of this change? Does it affect the serialization?

[JeremyKuhne]

Resolved with: #9104