Fix: Finish migration to Webpack 5, add ProvidePlugin for process polyfill to resolve "process is not defined" error

[bghcore]

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Description

Fixes "process is not defined" error occurring in CICD fresh builds by properly configuring webpack 5 to polyfill Node.js process global for browser environments.

Problem

After upgrading to webpack 5 in v0.5.20, the SDK bundle was failing in CICD with ReferenceError: process is not defined. This error occurred because:

• Webpack 5 removed automatic Node.js polyfills that were present in webpack 4
• The axios dependency uses process.nextTick internally
• The SDK's webpack config had resolve.fallback but was missing ProvidePlugin to inject the global
• Local builds worked due to webpack filesystem caching, but CICD fresh builds exposed the issue

Changes

1. webpack.common.js
   - Added webpack.ProvidePlugin to automatically inject process/browser polyfill when code references process global
   - Added resolve.fallback configuration for process/browser
2. package.json
   - Added process@0.11.10 to devDependencies
   - Bumped version to 0.5.21
3. CHANGELOG.md
   - Documented the fix and changes for v0.5.21

Solution Proposed

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Acceptance criteria

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Test cases and evidence

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Sanity Tests

• You have tested all changes in Popout mode
• You have tested all changes in cross browsers i.e Edge, Chrome, Firefox, Safari and mobile devices(iOS and Android)
• Your changes are included in the CHANGELOG

A11y

• You have run the Automated Accessibility Check and have no reported issues

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