Deprecate _WKWebsiteDataStore in favor of WKWebsiteDataStore

Deprecate _WKWebsiteDataStore in favor of WKWebsiteDataStore
https://bugs.webkit.org/show_bug.cgi?id=143844

Reviewed by Dan Bernstein.

Source/WebKit2:

* Shared/API/Cocoa/WKFoundation.h:
* UIProcess/API/Cocoa/WKWebViewConfiguration.mm:
(-[WKWebViewConfiguration _validate]):
* UIProcess/API/Cocoa/WKWebViewConfigurationPrivate.h:
* UIProcess/API/Cocoa/_WKWebsiteDataRecord.h:
* UIProcess/API/Cocoa/_WKWebsiteDataStore.h:
* mac/postprocess-framework-headers.sh:

Tools:

* MiniBrowser/mac/AppDelegate.m:
(-[BrowserAppDelegate newPrivateWindow:]):
* MiniBrowser/mac/WK2BrowserWindowController.m:
(-[WK2BrowserWindowController initWithConfiguration:]):
(-[WK2BrowserWindowController fetchWebsiteData:]):
(-[WK2BrowserWindowController fetchAndClearWebsiteData:]):
(-[WK2BrowserWindowController clearWebsiteData:]):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@182930 268f45cc-cd09-0410-ab3c-d52691b4dbfc