Revamp analyzer diagnostic system

[ematipico]

Our analyzer currently works this way:

• recommended rules emit a diagnostic error
• non-recommended rules don't emit any diagnostic

This behaviour is different from the majority of linters/analyzers out there, and it's really confusing for people who use other tools. We intended to change it, so:

• lint rules will always have a severity (it will be Severity::Information by default)
• recommended rules won't change the severity of a rule

This means there could be lint rules that will have Severity::Warning rules and be recommended.

[Conaclos]

Are there some rationales for using Severity::Information by default instead of Severity::Warning?

[ematipico]

There are no particular rationales, feel free to propose something in here. Severity::Information is the Default implementation of Severity

[Conaclos]

Maybe we should use the default implementation of Severity that should be Severity::Off?

[ematipico]

That's a variant that doesn't exist in Severity. It's possible there's some misunderstanding, so instead of talking code, why don't you propose a "business logic" instead?