Remove custom project code in ISO19115-3.2008?

[josegar74]

Describe the bug

ISO19115-3.2008 has the following code that seems specific to a project. :

core-geonetwork/schemas/iso19115-3.2018/src/main/plugin/iso19115-3.2018/update-fixed-info.xsl

Lines 590 to 610 in 461ce04

	<!-- Sextant / Template adding nilReason attribut with withheld value
	for some protocols. -->
	<xsl:template match="cit:linkage" priority="10">
	<xsl:choose>
	<xsl:when test="
	contains(lower-case(string(../cit:protocol/gco:CharacterString)), 'db') or
	contains(lower-case(string(../cit:protocol/gco:CharacterString)), 'copyfile') or
	contains(lower-case(string(../cit:protocol/gco:CharacterString)), 'file')">
	<cit:linkage gco:nilReason="withheld">
	<xsl:apply-templates select="@*"/>
	<xsl:copy-of select="./*" />
	</cit:linkage>
	</xsl:when>
	<xsl:otherwise>
	<cit:linkage >
	<xsl:apply-templates select="@*"/>
	<xsl:copy-of select="./*" />
	</cit:linkage>
	</xsl:otherwise>
	</xsl:choose>
	</xsl:template>

@fxprunayre, should we remove this or it's relevant for other projects. If so maybe we need to update the comment.

[fxprunayre]

Most of the time when we have those protocols used to declare internal organization network resources it sounds good to hide them to public users. Maybe we can cover that properly with (or after) your latest changes done in #6869.