bug: "Import a theme" button does nothing

[sgoudham]

What happened?

Reproduction Steps

1. Open Revolt
2. Open User Settings
3. Click "Appearance"
4. Scroll down and click "Import a theme"

Actual Behaviour

No popup or message appears when the "Import a theme" button is clicked.

Console Logs:

Expected Behaviour

A popup appears allowing me to paste a theme string or a file popup to select a json file containing a theme.

Additional Comments

Method of Install: Linux AppImage
Version: 1.0.6

It seems like this was raised beforehand in #136 but was ultimately closed as not planned.