app-catalog: Fix UI bugs

[skoeva]

These changes address minor bugs in the app catalog UI.

Fixes: #149

[sniok]

Thanks for taking a look into this!

The install button turns light-blue on hover, let's keep it consistent with other black buttons we have in the app.

For example here's how cluster chooser button looks while hovered

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When typing into the search the whole page freezes up, it sends a request and rerenders everything on each key press

CPU profiler shows this

I'd suggest adding some form debouncing to search state updates. Alternatively you could try useDeferredValue hook, although usually for this case simple debouncing works a bit better

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I know this wasn't in the original issue but I've noticed that sometimes images are missing, looking at the url there's an undefined at the end of the path so maybe it wouldn't be hard to not show image at all when it's missing

[skoeva]

@sniok thanks for the input here, added those changes to the PR 😃

[sniok]

looks good, thanks!

[sniok]

@skoeva let's rebase and I'll merge this

[skoeva]

@sniok added an additional commit because the app would crash without setting the params, but should be good now