authorize-check for xlscollectionCrosswalk

[floriangantner]

References

• Fixes limit xls-collection-crosswalk to group members #422

Description

Implement interface method for fine granular check to export these crosswalks to specific groups

Instructions for Reviewers

List of changes in this PR:

• implement isAuthorized method, which was before by default true by the interface ItemExportCrosswalk
  • add group check copied from other Crosswalk Formats
• whitebox-Tests: depending on the configuration check if the crosswalk format is offered to Anonymous/Administrator users in the context-menu.
• Introduced new IntegrationTest to check the isAuthorized function
• configuration: allow access to Administrator and Anonymous (behavior as before)

	<bean class="org.dspace.content.integration.crosswalks.XlsCollectionCrosswalk" id="xlsCrosswalkCollection">
		<property name="allowedGroups">
			<list>
				<value>Administrator</value>
				<value>Anonymous</value>
			</list>
		</property>
	</bean>

Checklist

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