feat: add per-rule granular error suppression

[cgatt]

Fixes #1818

This does slightly change some behaviours, specifically by suppressing errors for suppressed rules. I'm torn as to whether this is a sufficiently large behavioural change to cause an issue, though as a rule I feel it is a better behaviour and cant think of a scenario where someone would have been relying on a suppressed rule throwing an error.

[dontirun]

though as a rule I feel it is a better behaviour and cant think of a scenario where someone would have been relying on a suppressed rule throwing an error.

Agreed! Thanks for the contribution. Can you add an example for suppressing validation failures to the README?

[cgatt]

though as a rule I feel it is a better behaviour and cant think of a scenario where someone would have been relying on a suppressed rule throwing an error.

Agreed! Thanks for the contribution. Can you add an example for suppressing validation failures to the README?

Updated the readme, and while I was at it realised that I should probably still respect Suppression Ignore Conditions when suppressing validation failures, so slightly refactored to ensure that occurs and added some tests to that effect.

[dontirun]

Nice!