Highlight all occurrences of a duplicated identifier

HLS (vscode) only highlights the first occurrence of duplicate identifiers, which - at first glance - looks like 'no errors'. Then like 'HLS dead?', and then I realize the squiggly I'm looking for is far up in the file I'm editing. There is information in GHC's error message to highlight both/all occurences.

HLS error message
```
[{
"resource": "/home/artur/projects/snip/src/Ex1.hs",
"owner": "Haskell (snip)",
"severity": 8,
"message": "Multiple declarations of ‘z’\nDeclared at: /home/artur/projects/snip/src/Ex1.hs:112:1\n /home/artur/projects/snip/src/Ex1.hs:137:1",
"source": "typecheck",
"startLineNumber": 137,
"startColumn": 1,
"endLineNumber": 137,
"endColumn": 2
}]
```

Inspecting the messages to check for `Multiple declarations of` prefix and issuing diagnostics at all relevant lines would be ideal.