fix: ErrorBoundary small styling changes

[AkshatJawne]

Closes #642

Clarification:

• Only added the centered error for widget related errors, as did not want to disturb the default for panel.py(since we still want non-errored panel to have the items aligned with flex-start), as noted here

  deephaven-plugins/plugins/ui/src/js/src/layout/ReactPanel.tsx

  Line 59 in 2dfbe0f

  // Apply the same defaults as panel.py

• Thus, the snippet in the original ticket is wrong, and we can test with any errored snippet, like the one below:

from deephaven import ui
@ui.component
def test_component():
    state, set_state = use_state(20)
    return state

testComp = test_component()

Image below of the icon no longer overflowing when it is made very short:

[dsmmcken]

This seems weird, can't you just give 100% width to the ui-widget-error-view isntead?

[AkshatJawne]

Ready for re-review

[dsmmcken]

Move the style stuff to a WidgetErrorView.scss, rather than inline.

[dsmmcken]

Not like this.

1. Make a file adjacent to this fill WidgetErrorView.scss
2. Place your style in it.
3. Do a regular import of it (vite will handle the rest) you don't need to ?inline and then put it in a style tag

[AkshatJawne]

I was told by @mofojed and @mattrunyon to have it like this, they did not want me to create a separate WidgetErrorView.scss, since it isn't really done like that anywhere else in plugins.

[mattrunyon]

We can't do regular css imports in plugins because they're distributed as a single JS file. Vite and other bundlers typically handle css imports by putting style tags in the index.html, but plugins can't do that

[mattrunyon]

That said, you shouldn't need to import the styles here. They should already be included in one of the top TS files

[AkshatJawne]

If I do not import, the styles don't apply @mattrunyon

[AkshatJawne]

Nvm, yeah they are included here -- had to hard refresh my page.

[dsmmcken]

We can't do regular css imports in plugins because they're distributed as a single JS file. Vite and other bundlers typically handle css imports by putting style tags in the index.html, but plugins can't do that.

Oh, didn't know that. Anyways, that's cleaner now thanks.