fix(amazonq): catch error for show document (aws#7112)

## Problem
catch error for show document it should not crash the server

## Solution


---

- 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.

Author: zixlin7

packages/amazonq/src/lsp/chat/messages.ts

@@ -295,10 +295,17 @@ export function registerMessageListeners(
     languageClient.onRequest<ShowDocumentParams, ShowDocumentResult>(
         ShowDocumentRequest.method,
         async (params: ShowDocumentParams): Promise<ShowDocumentParams | ResponseError<ShowDocumentResult>> => {
-            const uri = vscode.Uri.parse(params.uri)
-            const doc = await vscode.workspace.openTextDocument(uri)
-            await vscode.window.showTextDocument(doc, { preview: false })
-            return params
+            try {
+                const uri = vscode.Uri.parse(params.uri)
+                const doc = await vscode.workspace.openTextDocument(uri)
+                await vscode.window.showTextDocument(doc, { preview: false })
+                return params
+            } catch (e) {
+                return new ResponseError(
+                    LSPErrorCodes.RequestFailed,
+                    `Failed to open document: ${(e as Error).message}`
+                )
+            }
         }
     )