New document builder must take null values with consistent behavior

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: Master
• Fix Version/s: 7.2.0 GA1
• Component/s: Search Infrastructure
• Labels: None
• Fix Priority: 4
• Epic Link: Search capabilities in 7.2
• Sprint: Search | S02 Sprint 19
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/73339

Fluent interface friendly when setting directly from another object's getters.

• typed single setter with null: unset the field
• typed multi setter with single null: unset the field
• typed multi setter with array of single null: unset the field
• typed multi setter with vararg multi nulls: set multi nulls
• typed multi setter with array of multi nulls: set multi nulls
• untyped single setter with null: unset the field
• untyped multi setter with null: unset the field
• untyped multi setter with collection of single null: set single null
• untyped multi setter with collection of multi nulls: set multi nulls