Add a separate object that represents a remote object invocation

Add a separate object that represents a remote object invocation
https://bugs.webkit.org/show_bug.cgi?id=150639

Reviewed by Tim Horton.

* Shared/API/Cocoa/RemoteObjectInvocation.h: Copied from Source/WebKit2/Shared/API/Cocoa/RemoteObjectRegistry.h.
(WebKit::RemoteObjectInvocation::interfaceIdentifier):
(WebKit::RemoteObjectInvocation::encodedInvocation):
* Shared/API/Cocoa/RemoteObjectInvocation.mm: Copied from Source/WebKit2/Shared/API/Cocoa/RemoteObjectRegistry.mm.
(WebKit::RemoteObjectInvocation::RemoteObjectInvocation):
(WebKit::RemoteObjectInvocation::encode):
(WebKit::RemoteObjectInvocation::decode):
* Shared/API/Cocoa/RemoteObjectRegistry.h:
* Shared/API/Cocoa/RemoteObjectRegistry.messages.in:
* Shared/API/Cocoa/RemoteObjectRegistry.mm:
(WebKit::RemoteObjectRegistry::sendInvocation):
(WebKit::RemoteObjectRegistry::invokeMethod):
* Shared/API/Cocoa/_WKRemoteObjectRegistry.mm:
(-[_WKRemoteObjectRegistry _sendInvocation:interface:]):
(-[_WKRemoteObjectRegistry _invokeMethod:]):
* Shared/API/Cocoa/_WKRemoteObjectRegistryInternal.h:
* WebKit2.xcodeproj/project.pbxproj:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@191810 268f45cc-cd09-0410-ab3c-d52691b4dbfc