MFH: r520359 sysutils/py-scandir: Fix unicode issues, level up ports compliance

This change fixes tests and likely runtime in certain locale environments
by replace the existing test_scandir.py patch with a backported upstream
patch from PR #109 [1][2], coupled with setting an appropriate locale.

While I'm here:

• Strip shared library and add LICENSE_FILE

Tests now all pass on all Python versions (2.7-3.8)

[1] https://github.com/benhoyt/scandir/pull/109
[2] https://github.com/benhoyt/scandir/issues/122

Approved by: portmgr (blanket: ports compliance, bugfix)

Approved by: ports-secteam (blanket(s): ports compliance, bugfix)