fix(amazonq): add back line numbers next to code issue (#7810)

## Problem
There was previously a task "Remove `[Ln 34, Col 1]` from Code Issues
panel from each issue`". Originally, this was meant to just mean remove
`, Col 1`, but I interpreted it to mean remove the whole blob.

## Solution
This change adds the line back, but without the `, Col 1`

<img width="432" height="341" alt="image"
src="https://github.com/user-attachments/assets/63ed938d-7f2d-4718-8ca4-ceb5b4e50a96"
/>

---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

Co-authored-by: Blake Lazarine <[email protected]>
Co-authored-by: Laxman Reddy <[email protected]>

Author: 3 people

packages/amazonq/test/unit/codewhisperer/service/securityIssueTreeViewProvider.test.ts

@@ -150,7 +150,7 @@ describe('SecurityIssueTreeViewProvider', function () {
                         item.iconPath?.toString().includes(`${item.issue.severity.toLowerCase()}.svg`)
                     )
                 )
-                assert.ok(issueItems.every((item) => !item.description?.toString().startsWith('[Ln ')))
+                assert.ok(issueItems.every((item) => item.description?.toString().startsWith('[Ln ')))
             }
         })
     })

packages/core/src/codewhisperer/service/securityIssueTreeViewProvider.ts

@@ -189,8 +189,11 @@ export class IssueItem extends vscode.TreeItem {
     }
 
     private getDescription() {
+        const positionStr = `[Ln ${this.issue.startLine + 1}]`
         const groupingStrategy = CodeIssueGroupingStrategyState.instance.getState()
-        return groupingStrategy !== CodeIssueGroupingStrategy.FileLocation ? `${path.basename(this.filePath)}` : ''
+        return groupingStrategy !== CodeIssueGroupingStrategy.FileLocation
+            ? `${path.basename(this.filePath)} ${positionStr}`
+            : positionStr
     }
 
     private getContextValue() {