Implement Method to Release Licenses Without a Server Roundtrip

Merge from Widevine repo of http://go/wvgerrit/52480

Partners have asked for a way to release offline licenses without
using a release message. This is typically used by cable partners who
are caching licenses ahead of time and do not care about usage
statistics.

As part of implementing this request, CdmSession::DeleteLicense() was
renamed to reflect that it only deletes the *files* associated with a
license, and a new CdmSession::DeleteLicense() has been written that
also cleans up other related data.

Bug: 77955334
Test: CE CDM Unit Tests
Test: tested as part of http://go/ag/4674759
Change-Id: I00d6e20935c5fecb3ac9be6757c0f191d85c6bd6

libwvdrmengine/cdm/core/test/test_printers.cpp

@@ -601,6 +601,8 @@ void PrintTo(const enum CdmResponseType& value, ::std::ostream* os) {
       break;
     case DEVICE_CANNOT_REPROVISION: *os << "DEVICE_CANNOT_REPROVISION";
       break;
+    case SESSION_NOT_FOUND_19: *os << "SESSION_NOT_FOUND_19";
+      break;
     default:
       *os                                        << "Unknown CdmResponseType";
       break;