XmlMerger: Rework Combine Text Nodes

[hohwille]

In review of PR #912 we found a problematic edge-case here:

IDEasy/cli/src/main/java/com/devonfw/tools/ide/merge/xmlmerger/MergeStrategy.java

Lines 162 to 166 in 6f167c1

	} else if (updateChild.getNodeType() == Node.TEXT_NODE || updateChild.getNodeType() == Node.CDATA_SECTION_NODE) {
	if (!updateChild.getTextContent().isBlank()) {
	replaceTextNode(targetElement, updateChild);
	}
	}

From the review:

Every non-empty text node will be replaced using this method and replace the text into the first non-blank text node.
So if you have
template: Text(text1) CDATA(text2) Text(text3)
workspace: Text(text4) CDATA(text5) Text(text6)
you will create

    iteration: Text(text1) CDATA(text5) Text(text6)
    iteration: Text(text2) CDATA(text5) Text(text6)
    iteration: Text(text3) CDATA(text5) Text(text6)