listener: allow rebuild listener if the num of addresses are not changed but values are changed

[Shikugawa]

Commit Message: listener: allow rebuild listener if the num of addresses are not changed but values are changed
Additional Description:
When updating a Listener with the same name via LDS, the update gets rejected if the number of contained ports remains unchanged.

For example, consider the following existing Listener:

name: foo
address:
  socket_address:
    address: 127.0.0.1
    port_value: 1000
additional_addresses:
- address:
    socket_address:
      address: 127.0.0.2
      port_value: 1000

If the Listener is updated as follows:

name: foo
address:
  socket_address:
    address: 127.0.0.1
    port_value: 2000
additional_addresses:
- address:
    socket_address:
      address: 127.0.0.2
      port_value: 1000

But it's rejected.

We expect it should work: As long as there is no other Listener with conflicting ports, the existing Listener with the same name should be drained and then reconfigured instead of being outright rejected.

This fix involves a small-scale refactoring along with a small potential bug fix that the function hasCompatibleAddress() does not immediately return false when socket options are changed, then listener rebuild is not invoked.

Risk Level: Low
Testing: Unit
Docs Changes: N/A
Release Notes: N/A
Platform Specific Features:
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