show 'rule name' / 'error code' from in diagnostics on hover

[failable]

Check for existing issues

• Completed

Describe the feature

Show diagnostic code in hover. Currently it is not shown in the hover

but is shown in the diagnostics view (reportUnknownMemberType in this case)

When there are many diagnostics, it's hard to locate the target one in the diagnostic list view and figure out the error code for further action (e.g. google search its meaning or insert a noqa comment).

It would also be nice If the error code in the hover is copyable.

If applicable, add mockups / screenshots to help present your vision of the feature

No response

[notpeter]

This appears to impact multiple languages, here is an example of it happening in Rust too (E0425)

Thanks for reporting.