feat: setup in source config for functions

[jackiewmacharia]

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Summary

Related to:

• https://github.com/netlify/pillar-runtime/issues/200
• https://github.com/netlify/pod-compute/issues/97

Builds upon:

• feat: add support to per-function configuration files #1030

This PR provides in source configuration for functions. Test it out with the below function:

import { Handler } from '@netlify/functions'

const config = {
  nodeBundler: 'esbuild',
  includedFiles: ['blog/*.md']
}

const handler: Handler = async (event, context) => {
  const { name = 'stranger' } = event.queryStringParameters

  return {
    statusCode: 200,
    body: JSON.stringify({
      message: `Hello, ${name}!`,
    }),
  }
}

export {
  handler, config
}

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[github-actions]

⏱ Benchmark results

Comparing with 20fe86c

largeDepsEsbuild: 6.2s

⬆️ 5.35% increase vs. 20fe86c

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└───┴──┴────┴──┴────┴──┴──>
    T-2     T-1      T    

Legend

• T-2 (871b138): 5.9s
• T-1 (20fe86c): 5.9s
• T (current commit): 6.2s

largeDepsNft: 29.3s

⬆️ 0.52% increase vs. 20fe86c

^  29.2s   29.1s   29.3s  
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└───┴──┴────┴──┴────┴──┴──>
    T-2     T-1      T    

Legend

• T-2 (871b138): 29.2s
• T-1 (20fe86c): 29.1s
• T (current commit): 29.3s

largeDepsZisi: 44.6s

^  43.7s           44.6s  
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└───┴──┴────────────┴──┴──>
    T-2     T-1      T    

Legend

• T-2 (871b138): 43.7s
• T-1 (20fe86c): n/a
• T (current commit): 44.6s

[jackiewmacharia]

Converting back to draft since we will go with per file configuration for now.