chore: refactor provider

[AlinsRan]

Type of change:

• Bugfix
• New feature provided
• Improve performance
• Backport patches
• Documentation
• Refactor
• Chore
• CI/CD or Tests

What this PR does / why we need it:

Description

This commit refactors the adc provider module with the goal of optimizing package structure, reducing module coupling, and improving code maintainability and extensibility.

Changes include

1. Directory and package structure reorganization
   • Moved code from the original internal/provider/adc directory to a new internal/adc directory.
   • Split the code into sub-packages such as cache, client, and translator, with clearer responsibilities.
   • Split configuration management into a configmanger component
2. Decoupling and responsibility separation
   • Extracted caching, execution, and resource translation logic from the provider core into separate modules to reduce internal dependencies.

Reason for the changes

• In the old structure, the adc provider’s various functionalities were tightly coupled at the same level, making maintenance and extension costly.
• With modular separation, it becomes easier to perform unit testing, replace implementations, or introduce new functional modules in the future.

Pre-submission checklist:

• Did you explain what problem does this PR solve? Or what new features have been added?
• Have you added corresponding test cases?
• Have you modified the corresponding document?
• Is this PR backward compatible? If it is not backward compatible, please discuss on the mailing list first

[juzhiyuan]

Just a reminder: when marking this PR as ready for review, please fill in the description and checklist completely.

[ronething]

lgtm

[bzp2010]

The latest version is 0.7.0, why can't we use latest?

[AlinsRan]

https://github.com/apache/apisix-ingress-controller/actions/runs/16980187972/job/48138378106

Go.mod uses 1.23

[bzp2010]

Based on what go releases have done, it doesn't seem to make sense for us to be stuck with older versions, newer versions always include CVE security fixes and runtime improvements.

Maybe we should upgrade it in a later PR.