Introduce initAfterInsert() framework function

[magnesj]

Fixes #14401

Introduce caf::PdmXmlObjectHandle::initAfterInsert() combining the manual resolveReferencesRecursively() + initAfterReadRecursively() pair that must be called after inserting a copied object into the document tree. The function resolves references first so that initAfterRead() overrides can rely on resolved pointer fields, and asserts that the object has a parent field to catch calls made before insertion (the bug class behind #14372).

Intentionally not migrated:

• RiaApplication project load and RicSummaryPlotTemplateTools/RicPasteSummaryCurveFeature, which interleave other work between resolve and init
• cafTestApplication document load, which operates on a root object with no parent field
• Sites calling only one of the two functions (candidates for follow-up after individual review, see Introduce initAfterInsert() to combine resolveReferencesRecursively() and initAfterReadRecursively() #14401)

A unit test in cafPdmAdvancedTemplateTest.cpp verifies that initAfterInsert() resolves a nulled pointer field and re-runs initAfterRead() on an inserted copy.