Fix S1643 FP: should not apply when strings are not aggregated

[cristian-ambrosini-sonarsource]

Fixex #5521 + structure refactoring.

[martin-strecker-sonarsource]

Looks like a nice change. Some more improvements are possible

[martin-strecker-sonarsource]

Consider changing the parameter names.
Also: There seem to be FPs in the ITs.

[martin-strecker-sonarsource]

There seem to be FPs in the ITs

[cristian-ambrosini-sonarsource]

There seem to be FPs in the ITs

Emh, while fixing those FPs I "had" to fix #5521 within the same PR.

[martin-strecker-sonarsource]

Wating for the equivalence comment to be resolved.

[martin-strecker-sonarsource]

LGTM. You can improve coverage with something like

var i = 1 - 1 + 1;

or so.

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
No Duplication information

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

100.0% Coverage
0.0% Duplication

[cristian-ambrosini-sonarsource]

Peach validation:

• 81 lost issues: most of them are not related to this specific issue but to the addition of context.SemanticModel.GetSymbolInfo(assigned).Symbol is ILocalSymbol check.
  That removed issues where the string was just a field or property inside another class , of key/value of a dictionary.
  While I'm fine with those, as already discussed, I found one TN that needs to be investigated/addressed. Moreover, we lost also some string fields/properties declared outside the method. I think those are TNs as well.
  Some of them were just referencing a method parameter and those should be skipped because it may be part of some interface.

We need to take another look at this rule before the release.

[martin-strecker-sonarsource]

I created issue #7722 with the FNs for IParameterSymbols, IFieldSymbol and IPropertySymbols.