Fix Button ellipsis & Stack.Item overgrowing

[AyIong]

About the PR

Fixes buttons ellipsis with icon #78
Also, ellipsis now works inside Stack.Item, for example:

<Stack fill>
  <Stack.Item grow>
    <Button fluid ellipsis />
  </Stack.Item>
</Stack>

It will work as it should and text inside the button will be properly cuted, IF you set grow prop.

What about Stack.Item overgrowing? Well...
I set the minimum height and width of Stack.Item with grow to zero, so it can now shrink and fill ONLY the available space. Although I'm sure that in some situations it can still go beyond the allowed space. Let's hope I don't accidentally break one of the hundreds of UI's.

Video

chrome_tPp1laacmt.mp4

Why's this needed?

Little more flexible Stack and proper button ellipsis

[tgstation-ci]

Thank you for contributing to tgui-core! The workflow 'Chromatic Security' requires repository secrets and will not run without approval. Maintainers can add the CI Cleared label to allow it to run. Note that any changes to chromaitc-security.yml and chromatic.yml will not be reflected.

[AyIong]

Thank you for contributing to tgui-core! The workflow 'Chromatic Security' requires repository secrets and will not run without approval. Maintainers can add the CI Cleared label to allow it to run. Note that any changes to chromaitc-security.yml and chromatic.yml will not be reflected.