feat: plugins in multi-auth returns error instead of logging it

[shreemaan-abhishek]

Description

When using auth plugins with the multi auth plugin, if one of the authentication fails but other auth plugins succeed, the basic auth plugin will record a warning log, causing inconvenience to the user.

apisix/apisix/plugins/multi-auth.lua at master · apache/apisix The muti auth plugin does not record the error message returned by the plugin.

Solution:

When there are multiple plugins in muti auth, if the final verification is passed (that is, any plugin is verified), even if other plugins return errors, no error log needs to be recorded
If all plugins fail to verify, summarize the error messages of multiple plugins into a log for recording.

Checklist

• I have explained the need for this PR and the problem it solves
• I have explained the changes or the new features added to this PR
• I have added tests corresponding to this change
• I have updated the documentation to reflect this change
• I have verified that this change is backward compatible (If not, please discuss on the APISIX mailing list first)