fix: package json name and deps, always set generateSecrets prop

[abhi7cr]

Description of changes

QA bug fixes:

• Do not replace package.json dependencies and devDependencies. Only override ones that are needed.
• Pin dependencies to match the versions set in create-amplify npx command
• Set generateSecret: false when ClientSecret is not defined. This will prevent creation of a new user pool client post refactor
• Preserve package.json name
• Change logical id of user pool client to indicate its a Native one

Description of how you validated changes

Manual testing, unit tests

Checklist

• PR description included
• yarn test passes
• Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)
• New AWS SDK calls or CloudFormation actions have been added to relevant test and service IAM policies
• Pull request labels are added

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.