Add plugin setting for minio CDN endpoint support

[li2go]

Change Summary

Provide summary of changes with issue number if any.

Change type

• feat: (new feature for the user, not a new feature for build script)
• fix: (bug fix for the user, not a fix to a build script)
• docs: (changes to the documentation)
• style: (formatting, missing semi colons, etc; no production code change)
• refactor: (refactoring production code, eg. renaming a variable)
• test: (adding missing tests, refactoring tests; no production code change)
• chore: (updating grunt tasks etc; no production code change)

Test/ Verification

Provide summary of changes.

Additional information / screenshots (optional)

For some well-known reasons, we usually do not use the standard endpoint/bucket/key mode to access resource files.

Solve this problem by adding a setting that will use the CDN address when necessary for resource display.
By applying this setting, it is possible to alleviate the implementation difficulties of some other compatible solutions.

Anything for maintainers to be made aware of

[CLAassistant]

All committers have signed the CLA.

[wingkwong]

1. please test it once and provide a video for demonstration. So far your changes in this PR are not reflected in UI since it is still taking 0.0.1.
2. if Minio CDN Endpoint is provided, does it mean that Minio endpoint is no longer required?