NetworkPkg/NetLib: Replace __FILE__ with __FILE_NAME__ in NetLib

[r1chard-lyu]

This change helps to:

• Shorten the file name displayed in debug logs, reducing the overall file size.

• Avoid exposing full directory structures in build output, enhancing portability between different build environments.

• Breaking change?

  • Breaking change - Does this PR cause a break in build or boot behavior?
  • Examples: Does it add a new library class or move a module to a different repo.

• Impacts security?

  • Security - Does this PR have a direct security impact?
  • Examples: Crypto algorithm change or buffer overflow fix.

• Includes tests?

  • Tests - Does this PR include any explicit test code?
  • Examples: Unit tests or integration tests.