[curl] Unify CookieJarCurlDatabase and the abstract class CookieJarCurl

[curl] Unify CookieJarCurlDatabase and the abstract class CookieJarCurl
https://bugs.webkit.org/show_bug.cgi?id=191620

Reviewed by Alex Christensen.

Remove a abstract class CookieJarCurl which is not needed anymore.
And, rename CookieJarCurlDatabase to CookieJarCurl.

No new tests because there's no behaviour change in WebCore.

* platform/Curl.cmake: Replaced CookieJarCurlDatabase.cpp with CookieJarCurl.cpp.
* platform/network/curl/CookieJarCurl.cpp: Renamed from Source/WebCore/platform/network/curl/CookieJarCurlDatabase.cpp.
* platform/network/curl/CookieJarCurl.h: Merged CookieJarCurl.h and CookieJarCurlDatabase.h.
* platform/network/curl/CookieJarCurlDatabase.h: Removed.
* platform/network/curl/NetworkStorageSessionCurl.cpp:
(WebCore::NetworkStorageSession::NetworkStorageSession): Replaced CookieJarCurlDatabase with CookieJarCurl.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@238176 268f45cc-cd09-0410-ab3c-d52691b4dbfc