External Link Checker UI: improve UI and provide download

[#1]

Request for Feature Enhancement (RFE) Summary:	Enhance External Link Checker page
Use-case:	As en editor I want know about broken external on my website which I'm responsible for and want to fix the links efficiently.
Current/Experienced Behavior:	Under /etc/linkchecker.html you get a list which but you can not export it to a csv. Imaging you have a lot of editors working on AEM instance each responsible for different subtrees reflecting different business groups. Now it is hard to figure out the error for specific paths in order to fix this. It is even harder if error occurs not just on a single page but in blueprint page and the connected livecopy pages (imagine 20 livecopies) - here the column get's flooded (just very long comma separated list) and hard to retrieve the information out of that. Link to documentation: https://experienceleague.adobe.com/docs/experience-manager-65/content/sites/administering/operations...
Improved/Expected Behavior:	Enhance the existing overview with option to export: with the exported list you could filter for paths in the referrer column and assign the list to responsible editors. Maybe a filtering directly in the UI regarding the referrer column would be even better, to see just the paths of /content which I'm responsible for not the ones of whole instance and to export this filtered view. It would be even better if I would informed about broken external links via email providing all the necessary information, meaning path to page and the external link which is not working there.
Environment Details (AEM version/service pack, any other specifics if applicable):
Customer-name/Organization name:	Carl Zeiss AG
Screenshot (if applicable):
Code package (if applicable):

[#2]

@lutzU 

Thanks for proposing this idea

This has been reported to the engineering under the internal reference SITES-20521. The product team will triage this request to verify feasibility based on the prioritization model. This post will be updated according to the Jira request status.