Improve flow step navigation

Flow steps can belong to different parts of the same line.
This commit makes selections more precise by including column information from the SARIF step data.

Author: wwong

src/main/kotlin/com/github/adrienpessu/sarifviewer/services/SarifService.kt

@@ -134,7 +134,13 @@ class SarifService {
         val element = Leaf(
                 leafName = result.message.text ?: "",
                 address = "${result.locations[0].physicalLocation.artifactLocation.uri}:${result.locations[0].physicalLocation.region.startLine}",
-                steps = result.codeFlows?.get(0)?.threadFlows?.get(0)?.locations?.map { "${it.location.physicalLocation.artifactLocation.uri}:${it.location.physicalLocation.region.startLine}" }
+                steps = result.codeFlows?.get(0)?.threadFlows?.get(0)?.locations?.map {
+                    "${it.location.physicalLocation.artifactLocation.uri}:" +
+                            "${it.location.physicalLocation.region.startLine}:" +
+                            "${it.location.physicalLocation.region.startColumn}:" +
+                            "${it.location.physicalLocation.region.endLine}:" +
+                            "${it.location.physicalLocation.region.endColumn}"
+                }
                         ?: listOf(),
                 location = result.locations[0].physicalLocation.artifactLocation.uri,
                 ruleId = result.ruleId,