Feature/validate sheriff config and fix integration tests

[tomwhite007]

This PR is a branch off #179 at 2b08dbd because the integration tests start to have an environmental issue at that point; they work locally but fail in the pipeline e.g.

9,10c9,10
<         "line": 5,
<         "column": 3,
---
>         "line": 6,
>         "column": 5,
13,14c13,14
<         "endLine": 12,
<         "endColumn": 4
---
>         "endLine": 11,
>         "endColumn": 6 ... etc

I've created this draft PR to hunt the problem down

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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