Apply "AND" of multiple linked PRs for a single issue to be closed or allow non-closing linked PRs

[achimnol]

Currently the linked PRs can be connected only by stating that "it resolves/fixes/closes" the issue.
As #4619 suggests, I'd like to have an option to just "refer" an issue without closing it when merged.

Also, I'd like to set the closing condition to be the "AND" combination of all linked PRs when there are multiple linked PRs to a single issue. I have this pattern very frequently because the work scope of a single issue often spans across multiple different components (repositories) to fix up. Currently, closing just one of linked PRs closes the issue, when still there are open linked PRs, meaning that it is working as an "OR" combination.

Here is an example case:

I'd like to close the issue only when ALL linked PRs are successfully merged, not only one of them.

2022/02/24 update

Probably, we need to consider cases that PRs are rejected/cancelled and new PRs are added to replace them. In that case, we could automatically replace the reference prefix to just "refs" to indicate the relevance but not the dependence, along with #4619.

Also we could keep the backward compatibility by introducing new prefixes such as "required by".