Add lifecycle_link key to info.yml files

lifecycle_description, like the module has a name and description?

E.g. if forum module was deprecated, the action would be 'Move to the Forum contributed module'

I think it would be good for these to link to a page on Drupal.org rather than directly to replacement modules, this way we can update the documentation page over time without needing to update core. This brings up the question do we always want a custom message, or would a standard message with lifecycle_link key work?

+++ b/core/lib/Drupal/Core/Extension/InfoParserDynamic.php
@@ -108,14 +108,23 @@ public function parse($filename) {
+        if (!filter_var($parsed_info[ExtensionLifecycle::LIFECYCLE_LINK_IDENTIFIER], FILTER_VALIDATE_URL)) {

URL validation is tricky, and reminds me about #295021: Expand/augment UrlHelper::isValid() to improve correctness and handle more URL types

@andypost: hm, the sub-issues linked from #295021: Expand/augment UrlHelper::isValid() to improve correctness and handle more URL types have all been resolved. Not sure what's left of that at this point? Also that less used link protocols are not supported does not really concern this issue IMHO. That would not stop people from being able to assign a docs link.

I think the validation looks good, the tests are comprehensive. UI exposure of the value is in other issues. The requirement for this came from a UX team meeting last week to present this to users as remediation for the warning shown. So IMHO good to proceed.

Ps. the test link looks fun :D

Committed 3726333 and pushed to 9.3.x. Thanks!

We need to update https://www.drupal.org/node/3215042 still.

Updated https://www.drupal.org/node/3215042/revisions/view/12360437/12360446 :)