Remove use of global static `TypeFactory` singleton from 3.0

[cowtowncoder]

Describe your Issue

(note: offshoot of FasterXML/jackson-core#1321)

Unlike all other caches, cache for the default instance of TypeFactory is not bound to one specific ObjectMapper and can therefore lead to unintended Class retention.
This should not happen: each ObjectMapper should have its own TypeFactory instead of global singleton.

Change is probably not possible for 2.x but should be doable for 3.0.

[cowtowncoder]

Did refactor 2.x code to reduce usage of TypeFactory.defaultInstance() but the actual removal has to go in 3.0.