fix: import custom component from local directory

[dpilch]

Custom components attempted to import from amplify-ui rather than a local import.

• Custom components use local import
• Add support for default imports on import collection
• Move custom component related renderer function to CustomComponentRenderer
• Retain unofficial support of all primitives

[dpilch]

I was worried the local imports would break the type declarations, but this appears to be working fine.

[frimfram]

• what is the difference between findChildOverrides and getChildOverrrides?
• is findChiildOverrides available in amplify-ui already? if not, it may result in errors

[dpilch]

1. I'm not sure. Waiting for a response from Hector. Going based on the golden files for this requirement.
2. Yes

[alharris-at]

Pending investigation on that findChildOverrides v. getOverridesForType or whatever, but I'm also fine publishing that as a followup, since both helpers do exist.

[dpilch]

From Chris on findChildOverrides

I think it was intended do allow nested props for child components to be fetched but after talking this morning, I believe Harrison confirmed we won’t allow that.

So we should use getOverrideProps.

I'll confirm with Harrison, but like Al said we can merge this then follow up if needed.