Modifier reused - use code flow analysis

[aasitnikov]

Improves ModifierReusedDetector

1. Use DataFlowAnalyzer: It replaces the use of obtainAllModifierNames(), and directly tracks references, not just names. This catches more cases of modifier uses, such as tricky Row(modifier = Modifier.then(modifier))
2. Report only modifier reference location: Instead of reporting the whole method call, report the specific locations where the modifier is being used. This reduces visual clutter and makes problematic modifier uses more visible.
3. Code flow analysis: Use CFA to detect if modifier is being used multiple times. This allows to write code that was previously considered incorrect:

@Composable
fun Image(modifier: Modifier = Modifier) {
    if (LocalInspectionMode.current) {
        PreviewImage(modifier)
        return
    }
    AsyncImage(modifier)
}

CFA treats blocks and lambdas like simple blocks of code, and also tracks the control flow of return statements and if/when statements. If control flow graph contains path that has two or more such calls, they will be reported.

[salesforce-cla]

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[salesforce-cla]

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[ZacSweers]

Can we pull this custom AST code out to its own file or package? And ideally with a lot more docs? This looks like it's adding quite a bit of complexity to the check on the face of it

[aasitnikov]

Sure

[aasitnikov]

Didn't extract custom AST into other file, but added a lot more docs and fixed a couple of bugs from previous version