Draft: relation inside metadata group in refer crosswalk

[floriangantner]

References

• Fixes handle relation inside group in refercrosswalk #385 #385 (if this fixes an issue ticket)

Description

extension of refercrosswalk to consider relation inside metadatagroup.

Instructions for Reviewers

Please add a more detailed description of the changes made by your PR. At a minimum, providing a bulleted list of changes in your PR is helpful to reviewers.

List of changes in this PR:

• added check/line, if some value is some placeholder if.nullorplaceholder. or if.not.nullorplaceholder
• extended group to consider if conditions and to consider relation to other items inside the group.

Some example template considering both changes above configuration might be:

   <Authors>
        @group.dc-contributor-author.start@
            <Author>
                <DisplayName>@dc.contributor.author@</DisplayName>
                @relation.dc-contributor-author.start@
                    <Person id="@virtual.id@">
                    	<PersonName>
                    		<FamilyNames>@virtual.personName.lastName@</FamilyNames>
                    		<FirstNames>@virtual.personName.firstName@</FirstNames>
                    	</PersonName>
		                <ORCID>https://orcid.org/@person.identifier.orcid@</ORCID>
	            </Person>
                @relation.dc-contributor-author.end@
                @if.not.nullorplaceholder.oairecerif-author-affiliation.start@
                    @relation.oairecerif-author-affiliation.start@
                        <Affiliation>
                            <OrgUnit id="@virtual.id@">
                            @if.metadata.dc-title.start@
                                <Name>@dc.title@</Name>
                            @if.metadata.dc-title.end@
                            @if.metadata.organization-identifier-ror.start@
                            	<RORID>@organization.identiifer.ror@</RORID>
                            @if.metadata.organization-identifier-ror.end@
                            @if.metadata.organization-identifier-crossrefid.start@
                                <FundRefID>https://doi.org/10.13039/@organization.identifier.crossrefid@</FundRefID>
                            @if.metadata.organization-identifier-crossrefid.end@
                            </OrgUnit>
                        </Affiliation>
                    @relation.oairecerif-author-affiliation.end@
                @if.not.nullorplaceholder.oairecerif-author-affiliation.end@
            </Author>
	  	@group.dc-contributor-author.end@
	</Authors>

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[floriangantner]

aligned to 2023.02.02 Release