fix: Prioritize find link info by permanent MAC address, with fallback to current address

[liangwen12year]

Enhancement:
Updated the link_info_find method to prioritize matching links by perm-address when it is valid and available. If the perm-address is unavailable (None or "00:00:00:00:00:00"), the method falls back to matching by address. Additionally, if ifname is provided, it takes precedence and returns the corresponding linkinfo immediately.

Reason:
The change resolves scenarios where multiple network interfaces might
share the same current MAC address (address), leading to potential
ambiguity in link matching. By prioritizing the permanent MAC address
(perm-address), the method provides a more precise and consistent match.
This is particularly crucial in environments with:

- MAC address spoofing or dynamic changes, where the current MAC
  address may not reliably identify the interface.
- Virtual interfaces or VLANs, which often lack a valid perm-address
  and rely on the parent interface's address.
- Ambiguity when multiple interfaces share the same address.

Result:
This change improves the robustness of MAC address matching by ensuring
that permanent addresses are prioritized while maintaining a reliable
fallback mechanism for interfaces with no permanent address.

Issue Tracker Tickets (Jira or BZ if any):

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 12 lines in your changes missing coverage. Please review.

Project coverage is 43.11%. Comparing base (89d7148) to head (b9eb99a).
Report is 24 commits behind head on main.

Files with missing lines	Patch %	Lines
library/network_connections.py	0.00%	12 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main     #749       +/-   ##
===========================================
+ Coverage   20.40%   43.11%   +22.71%     
===========================================
  Files          10       12        +2     
  Lines        1485     3124     +1639     
  Branches      436        0      -436     
===========================================
+ Hits          303     1347     +1044     
- Misses       1181     1777      +596     
+ Partials        1        0        -1     

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[liangwen12year]

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[richm]

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