Replace macros with multiple elements by splitting existing text runs/paragraphs instead of replacing them

[jensschuppe]

Description

setComplexValue() can only replace macros with a single OOXML element. #2562 tries to make it support Section elements for inserting a batch of elements (e.g. created from HTML).

This PR is a different approach with a separate method setElementsValue() which receives an array of elements and tries to split the paragraph or text element containing the macro variable instead of replacing it. No new paragraph is added if the replacement is inline-only (Text elements without a TextRun).

Checklist:

• I have run composer run-script check --timeout=0 and no errors were reported
• The new code is covered by unit tests (check build/coverage for coverage report)
• I have updated the documentation to describe the changes

[coveralls]

coverage: 96.803% (-0.4%) from 97.217%
when pulling 795f2ec on jensschuppe:replaceMacroMultipleElements
into 8b891bb on PHPOffice:master.