Fix panic index out of range (#289)

[pluvivanto]

Pull Request Template

Description

This is PR for issue 289.

I tried to replicate this in my windows env (win11 25H2 w/ windows terminal v1.23.20211.0) but couldn't. idk if it's because of the windows/terminal version or because my windows isn't English-based.
But according to the log in that issue, the panic came from updateTableMetadataOnChange when the tables list is empty.
The simplest fix would be adding checks before the GetItemText&GetCurrentItem call, which I did in this PR. Though we might still want to dig into why the table list is empty in the first place.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Ran unit and integration tests.
I also changed =? in DB_USER=?postgres to ?= because the integration tests were failing. Pretty sure it was a typo, but feel free to drop that if it wasn't.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have checked my code and corrected any misspellings