Related issues input should accept an issue ID without the pound sign prefix
### Summary
The related issue input box should accept an issue ID regardless if it is prefixed by a `#` or not:

The placeholder text in the input hints that the `#` is required, but I still intuitively paste a bare issue ID every time I interact with this control.
In addition, perhaps the placeholder text should read `#<issue id>` instead of `<#issue id>` - this would make it a bit more clear that the `#` is required.
issue