fix(commerce): replace barrel import with proper import

[Spuffynism]

As part of CAPI-496, we compared bundle sizes for different changes we wanted to make to headless and spotted issues with imports in the commerce package.

Running dependency cruiser to map a graph of dependencies in the packages/headless folder showed that index.ts was being included (full dependencies.svg file here):

npx depcruise --no-config \
  --exclude "^node_modules" \
  --output-type dot \
  src/commerce.index.ts > dependencies.out && dot dependencies.out -T svg -o dependencies.svg

We then found the source of the issue was product-listing-recent-results with:

npx depcruise --no-config \
  --exclude "^node_modules" \
  --output-type dot \
  --ts-config tsconfig.json \
  --do-not-follow "^src/index.ts" \
  --focus "^src/index.ts" \
  src/commerce.index.ts > dependencies.out && dot dependencies.out -T svg -o dependencies.svg

This PR replace the index.ts barrel import with the proper redux import.

[github-actions]

Pull Request Report

PR Title

✅ Title follows the conventional commit spec.

Bundle Size

File	Old (kb)	New (kb)	Change (%)
case-assist	209.5	209.5	0
commerce	297.4	253.9	-14.6
search	367.3	367.3	0
insight	332	332	0
product-listing	302.2	263.8	-12.7
product-recommendation	182.2	182.2	0
recommendation	224.4	224.4	0
ssr	361.4	361.4	0

[Spuffynism]

We still depend on a few bits and pieces that we could not depend on (slices, actions, etc.), but I don't think it's worth it to invest some more time in this at this time. Nonetheless, here they are:

• did you mean
• trigger
• folded result list
• breadcrumb
• history
• static-filter-set
• question-answering
• dictionary-field-context
• context
• search-hub
• search-and-folding

If one ever wishes to reduce the bundle size for commerce, these would be good starting points. Using the interactive mode with dependency cruiser can help identify these issues (interactive.html):

npx depcruise --no-config \
  --exclude "^node_modules" \
  --output-type dot \
  --ts-config tsconfig.json \
  src/commerce.index.ts | dot -T svg -Grankdir=TD | npx depcruise-wrap-stream-in-html > interactive.html && open interactive.html