Preserve all internal comments

[ArkaprabhaChakraborty]

While the external comments outside the root element tag cannot be preserved due to how the XML Tree is built by the TreeBuilder, the internal comments can be saved and this PR aims at that task

Related #395

[llxia]

• Please use the keyword Related instead of Resolves in the message. This PR only partially fix the issue. Merging this PR with keyword Resolves will close the linked issue. https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue

• Could you provide an example input and output in the comment?

[karianna]

@ArkaprabhaChakraborty Are you able to update the PR?

[ArkaprabhaChakraborty]

Yep, previously if comments were within the root element's body they were not preserved. So if we consider the following input:

<playlist xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../TKG/playlist.xsd">
     <!--Test playlist for the OpenJ9 project.-->
          <test>
		<testCaseName>jcstress_BooleanFencedTest</testCaseName>
		<command>$(JAVA_COMMAND) $(JVM_OPTIONS) -jar $(Q)$(LIB_DIR)$(D)jcstress-tests-all-20220908.jar$(Q) $(APPLICATION_OPTIONS) -t BooleanFencedTest; \
			$(TEST_STATUS)</command>
		<levels>

We would have lost the following tag:

 <!--Test playlist for the OpenJ9 project.-->

But now it will preserve all the comments under the root element. So the output now will be the same as the above input