Improve bundle chunk hashes and names

[steverep]

Proposed change

• Switch to xxhash64 instead of default md4 (much much faster and will be webpack's future default)
• Keep the full 64-bit hash encoded in base64url instead of hex (11 characters)
• Use the contenthash placeholder instead of chunkhash (the former has pretty much replaced the latter and has an extra optimization flag to make sure it's a true hash of the resulting file)
• Add the numeric id to the beginning of the non-initial chunk names (zero out any cross file collisions and so they cannot start with "-")
• Add naming for asset modules to mimic the chunks

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example configuration

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io