Adopt new Cloudscape UI across the entire portal

[mtfranchetto]

Description

Replace previous AWS UI design system with Cloudscape. While the two libraries, in theory, can be swapped freely, doing this migration required a rework of some components, as they weren't used in a Cloudscape-compatible way.

Fixes https://github.com/aws-samples/pcluster-manager/issues/261

Main changes

• replace aws-ui imports with Cloudscape (https://github.com/aws-samples/pcluster-manager/commit/8c41c5db8e24a6f84e179adfd4f299797831363c)
• remove the global layout wrapper in favor of a locally defined AppLayout component - previously the global AppLayout in combination with a locally overridden layout resulted in a double AppLayout for some pages, leading to unexpected paddings and spacings (https://github.com/aws-samples/pcluster-manager/commit/8584b7e493e05826e18e90cb64dca5306a25d693 and https://github.com/aws-samples/pcluster-manager/commit/8584b7e493e05826e18e90cb64dca5306a25d693)
• remove icons from buttons and Material UI (https://github.com/aws-samples/pcluster-manager/commit/8419deda2919f8b188261e1e9d462db4089bc486 and https://github.com/aws-samples/pcluster-manager/commit/3d0f6584fe0b8f5c2dd32683e20d1c23e75cd6f2)
• replace Babel with SWC as a build system, meaning faster builds! (https://github.com/aws-samples/pcluster-manager/commit/cc8bb9de5e65fbfcf7855b541012cf81de8a7e8e)
• removed a lot of custom CSS rules to leverage Cloudscape styles (https://github.com/aws-samples/pcluster-manager/commit/9f62ed3f8410cef027244a54eb50a3e24fafb783)

How Has This Been Tested?

Manual tour of every section of the portal, making sure the UI is consistent across every page, on both Chrome and Firefox

UI

PR Quality Checklist

• [ ] I added tests to new or existing code
• [ ] I removed hardcoded strings and used our i18n solution instead (see here)
• [ ] I made sure no sensitive info gets logged at any time in the codebase (see here) (e.g. no user info or details, no stacktraces, etc.)
• [ ] I checked that infrastructure/update_infrastructure.sh runs without any error
• [x] I checked that npm run build builds without any error
• [x] I checked that clusters are listed correctly
• [x] I checked that a new cluster can be created (config is produced and dry run passes)
• [ ] I checked that login and logout work as expected

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