feat(lambda-at-edge): support image optimization

[dphang]

Fixes: #725 by supporting the image optimizer introduced in Next.js 10 and hence the image component.

• Added new image lambda handler to handle image optimization requests only
• Most of this is a port of the Next.js server image-optimizer and related files, with a modification to retrieve the file from S3 instead (e.g for files in public directory).
• Added a bunch of node_modules used for sharp (image library). These have been specifically built for Lambda Node 12.x platform (using the lambdci/docker-lambda image) and added statically.

[codecov]

Codecov Report

Merging #829 (3ccd9b8) into master (468da0d) will decrease coverage by 0.35%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #829      +/-   ##
==========================================
- Coverage   80.69%   80.33%   -0.36%     
==========================================
  Files          57       63       +6     
  Lines        1937     2217     +280     
  Branches      434      500      +66     
==========================================
+ Hits         1563     1781     +218     
- Misses        314      376      +62     
  Partials       60       60              

Impacted Files	Coverage Δ
...ages/libs/lambda-at-edge/src/routing/redirector.ts	82.75% <0.00%> (ø)
...rless-components/nextjs-component/src/constants.ts	100.00% <0.00%> (ø)
packages/libs/lambda-at-edge/src/image-handler.ts	97.05% <0.00%> (ø)
...es/libs/lambda-at-edge/src/lib/sendEtagResponse.ts	57.14% <0.00%> (ø)
...ages/libs/lambda-at-edge/src/images/imageConfig.ts	100.00% <0.00%> (ø)
...ages/libs/lambda-at-edge/src/s3/s3RetryStrategy.ts	50.00% <0.00%> (ø)
...s/libs/lambda-at-edge/src/images/imageOptimizer.ts	75.00% <0.00%> (ø)
...ages/libs/lambda-at-edge/src/images/serveStatic.ts	37.50% <0.00%> (ø)
packages/libs/lambda-at-edge/src/build.ts	91.86% <0.00%> (+0.26%)	⬆️
...rless-components/nextjs-component/src/component.ts	91.30% <0.00%> (+0.51%)	⬆️
... and 1 more

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[dphang]

@danielcondemarin this is done, could you please review when you have some time?

Unfortunately I don't know how to exclude the sharp_node_modules files from appearing in the PR. But the changes are mostly in lambda-at-edge in the images directory (for image optimizer) and a new image-handler. There are also some changes in Next.js component to add the new cache behaviors. And of course, unit tests.

Will try to add more test coverage afterwards for imageOptimizer and also exclude some scripts from code coverage.

[danielcondemarin]

Do we need imgix, cloudinary, akamai here?

[dphang]

Actually I didn't try these other loaders, will check on it but I think they go directly to those URLs

[oddnavy]

Awesome work! 🤞 for a release including this one soon

[marcfielding1]

Hey guys, I can test this on a LOT of images if you'd like - this is in the alpha release?