Refactor/simplify `CreatableAutoSuggest` (too many `strictNullChecks` issues)

[fregante]

Originally posted by @BLoe in https://github.com/pixiebrix/pixiebrix-extension/pull/6683#discussion_r1368895783

Furthermore, this CreatableAutoSuggest component appears to only be used in one place, in SelectorSelectorWidget. I'm not sure if this was used in more places previously, but if we only need to support the one widget, then this whole thing can/should be simplified a TON. Probably can remove a bunch of the props and make the rest required, based on the one widget call-site.

This is related to the strictNullChecks upgrade.

We have two options:

• figure out how to handle the optional onCreateNew and renderCreateNew callbacks
• simplify the whole component to avoid unnecessary complexity

[github-actions[bot]]

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[grahamlangford]

completed