BaseTools/Scripts/PatchCheck: Address false error conditions

BaseTools/Scripts/PatchCheck: Address false error conditions

https://bugzilla.tianocore.org/show_bug.cgi?id=2406

* Always print subject line after the git commit id to make
  it easier to know the context of warnings or errors.
* Allow UTF-8 characters in subject line
* Error if subject line length > 75 without CVE-xxx-xxxxx present
* Error if subject line length > 92 with CVE-xxxx-xxxxx present
* If body line length is > 75, then print warning instead of error.

Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>