C++: Add settings dialog for pointer declaration formatting

The dialog is at Tools > Options > C++ > Code Style > Edit... > Pointers
and References.

Currently the settings are referenced when applying the following
QuickFixes:
 - Adapting function signature in declaration/definition
   (FunctionDeclDefLink)
 - Inserting declaration from definition (InsertDeclOperation)
 - Inserting definition from declaration (InsertDefOperation)
 - Extracting a function (ExtractFunctionOperation)
 - Add Local Declaration (AddLocalDeclarationOp::Operation)

In these cases the code style of the current project is used. If there
is no current project open, the current global code style is used.

Task-number: QTCREATORBUG-6169

Change-Id: I3e4e502b3103f7f754ac9b39594ad461d89d9304
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>