cni-server: reconcile ovn0 routes periodically

[zhangzujian]

• Make sure you have followed Kube-OVN Code Style.

What type of this PR

• Bug fixes

Which issue(s) this PR fixes:

Fixes #2962

WHAT

🤖 Generated by Copilot at dd1fac6

This pull request refactors some common logic for router reconciliation and enhances the subnet event handling and policy routing management in the daemon controller. It also fixes a nil pointer bug in controller_linux.go and removes an unnecessary function call in controller.go.

🤖 Generated by Copilot at dd1fac6

Sing, O Muse, of the cunning code reviewers
Who scanned the pull request with keen eyes
And praised the skillful mover of reconcileRouters
To a common file, where it could better serve the wise.

HOW

🤖 Generated by Copilot at dd1fac6

• Move reconcileRouters function from controller_linux.go to controller.go to make it platform-independent and reusable (link)
• Add nil check for event parameter in reconcileRouters to handle nil event case (link)
• Fix bug by passing pointer to reconcileRouters instead of value to update original event object (link)
• Add goroutine to periodically call reconcileRouters with nil event to ensure consistency of policy routing rules and routes (link)
• Remove redundant call to runGateway in loopEncapIpCheck (link)