chore: upgrade to new eslint and switch to flat config

[rix0rrr]

Centralize eslint config in a new package, @aws-cdk/eslint-config as well because it was duplicated too much.

Addresses linting/compilation problems that had gone unnoticed because of nonstandard package configs.

• Rename .eslintrc.js -> eslint.config.js everywhere for the new flat config (and update .gitignore and .npmignore at the same time)
• Introduce @aws-cdk/eslint-config to hold a centralized config for all packages in the monorepo.
• Found some .bak files that seem like they're just hanging out.
• Update all packages with eslint --fix to the new sets of rules.
• Custom resource handler tests were not being type checked and had a bunch of issues that needed to be fixed.
• quote-props -> @stylistic/quote-props
• Bulk suppressions for the Error rule in dedicated files, because the eslint tool doesn't allow adding suppression comments in bulk.

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[aws-cdk-automation]

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