Clear out previous query results as soon as a new query is executed

[jbruneFei]

Describe the bug
When running a query sometimes the previous results are still listed and it is not clear if those are from the current query or the previous one.

To Reproduce
Steps to reproduce the behavior:

1. Run a query
2. Change the query
3. Re-run the query

Expected behavior
The previous results should be cleared out immediately so as to avoid any confusion.

Screenshots

Desktop (please complete the following information):

• SQLTools Version 0.28.4

• VS Code Version: 1.100.2 (user setup)
  Commit: 848b80aeb52026648a8ff9f7c45a9b0a80641e2e
  Date: 2025-05-14T21:47:40.416Z
  Electron: 34.5.1
  ElectronBuildId: 11369351
  Chromium: 132.0.6834.210
  Node.js: 20.19.0
  V8: 13.2.152.41-electron.0
  OS: Windows_NT x64 10.0.26100

• OS: Windows

• Driver:

  • PostgreSQL/Redshift

• Database version: PostgreSQL 16.6 on x86_64-pc-linux-gnu, compiled by x86_64-pc-linux-gnu-gcc (GCC) 9.5.0, 64-bit

Additional context
The extension is great. Obrigado.