[Addon] Chartmuseum AWS S3 auth without keys and custom ingress class

[oanasc]

Description of your changes

Fixes #742 and #743

How has this code been tested?

I enabled the addon on a EKS cluster and ensured the charts are able to publish and access to S3 is possible using the credential chain with no aws key id and secret provided.
And for the ingress change I provided our ingress class and verified the ingress is working.

The only thing I don't know is if there should be any corresponding UX change for the addon parameters. Please point me upon review if there is something that needs updating

Checklist

I have:

• Title of the PR starts with type (e.g. [Addon] , [example] or [Doc]).
• Updated/Added any relevant documentation and examples.
• New addon should be put in experimental.
• Update addon should modify the version in metadata.yaml to generate a new version.

Verified Addon promotion rules

If this pr wants to promote an experimental addon to verified, you must check whether meet these conditions too:

• This addon must be tested by addon's e2e-test to guarantee this addon can be enabled successfully.
• This addon must have some basic but necessary information.
  • An accessible icon url and source url defined in addon's metadata.yaml.
  • A detail introduction include a basic example about how to use and what's the benefit of this addon in README.md.
  • Also provide an introduction in KubeVela documentation.
  • It's more likely to be accepted if useful examples provided in example dir.

[oanasc]

@charlie0129, @wangyikewxgm may I get a review on this please

[wonderflow]

LGTM besides the nit