Ignore copyright symbols inside URLs during copyright detection

[dikshaa2909]

Fixes #4724

Summary

This PR fixes a false-positive issue where ScanCode detects copyright
statements when a copyright symbol "(c)" appears inside a URL.

For example:

http://example.com/(c)/path

was incorrectly treated as a copyright candidate, even though it is part of a URL
and not an actual copyright statement.

Problem

The copyright candidate detection logic treated "(c)" inside URLs as a valid
copyright marker. This resulted in incorrect detections when scanning text files
containing URLs with "(c)" in their path.

Solution

• Updated the copyright candidate detection logic to ignore copyright markers
  that appear inside URLs.
• Added a regression test to prevent future regressions.

Tests

• Added test_copyright_symbol_inside_url_is_ignored
• All existing tests pass successfully.
• Verified locally before submission.

Checklist

• Reviewed contribution guidelines
• PR is descriptively titled and links the original issue
• Tests pass locally and in CI
• No merge conflicts
• Documentation update not required
• CHANGELOG update not required

Signed-off-by: dikshadeware@gmail.com