[nexus] Add changelogTemplate

[BiNZGi]

From #6424 to add changelogTemplate

[usta]

@BiNZGi this need a bit more work , older releases are not matching with current template , so we need link: "" for the versions which are lower than 3-59-0 . 3-59-0 and above working

[BiNZGi]

That's why I separated the PR 😏...

First check, found:
https://help.sonatype.com/en/sonatype-nexus-repository-3-58-0-release-notes.html
https://help.sonatype.com/en/sonatype-nexus-repository-3-57-0-release-notes.html
https://help.sonatype.com/en/sonatype-nexus-repository-3-54-0-release-notes.html
and below

[BiNZGi]

It looks like there is another pattern if a patch version is released, e.g.
https://help.sonatype.com/en/sonatype-nexus-repository-3-58-0---3-58-1-release-notes.html
https://help.sonatype.com/en/sonatype-nexus-repository-3-57-0---3-57-1-release-notes.html
https://help.sonatype.com/en/sonatype-nexus-repository-3-54-0---3-54-1-release-notes.html
https://help.sonatype.com/en/sonatype-nexus-repository-3-53-0---3-53-1-release-notes.html
https://help.sonatype.com/en/nexus-repository-3-47-0---3-47-1-release-notes.html
https://help.sonatype.com/en/nexus-repository-3-29-0---3-29-2-release-notes.html

I think that is possible to do with a special changelogTemplate.

[usta]

LGTM 💯 🥇 🎉

[marcwrobel]

Suggested change

	link: https://help.sonatype.com/en/sonatype-nexus-repository-{% assign dashedReleaseCycle = "__RELEASE_CYCLE__.0"|replace:".","-" %}{% assign dashedPatch = "__LATEST__"|replace:".","-"|split:"-"|slice:0,3|join:"-" %}{{ dashedReleaseCycle }}{% if dashedReleaseCycle != dashedPatch %}---{{ dashedPatch }}{% endif %}-release-notes.html
	link: https://help.sonatype.com/en/sonatype-nexus-repository-3-59-0-release-notes.html

I would rather directly set the link than using such complicated changelog template: all of the releases using this changelog template are EOL. WDYT ?