When printing an ObjC object, which is a pointer, lldb has handled it
the same way it treats any other pointer – printing only class name and
pointer address. The object is not expanded, its children are not shown.

This change updates `dwim-print` to print objc pointers by expanding (ie
dereferencing), with the assumption that it's what the user wants.

Note that this is currently possible using the `--ptr-depth`/`-P` flag.
With this change, when `dwim-print` prints root level objc objects, it's
the same effect as using `--ptr-depth 1`.

An (unmeasured) improvement to performance of `dwim-print` when used as `po`.

This change lifts the check for `note_shown` to the top of the lambda, to avoid all subsequent work when the hint has already been shown. The main effect is to avoid performing a regex match when the hint is not going to be shown.

This change also constructs the `std::regex` only once, by making it static.

There are a lot of lldb commands whose result is really one or more
ValueObjects that we then print with the ValueObjectPrinter. Now that we
have the ability to access the SBCommandReturnObject through a callback
(#125006), we can store the resultant ValueObjects in the return object,
allowing an IDE to access the SBValues and do its own rich formatting.

rdar://143965453

`frame variable` supports nested variable access, which the API calls "variable
expression paths". This change updates `dwim-print` to support a subset of supported
variable expression paths.

Consider the expression `a->b`. In C++, the arrow operator can be overloaded, and where
that is the case, expression evaluation must be used to evaluate it, not frame variable.
Likewise, the subscript operator can be overloaded.

To avoid those cases, this change introduces a limited support for variable expression
paths. Use of the dot operator is allowed.

Additionally, this change allows `dwim-print` to directly access children of `this` and
`self` (see AllowDirectIVarAccess). This functionality is also provided by the same
`GetValueForVariableExpressionPath` method.

rdar://104348908

We have helpers to emit warnings and errors. Do the same thing for notes
to they stand out more.

When an expression produces no result, set `dwim-print` status to 
`eReturnStatusSuccessFinishNoResult`.

ValueObject is part of lldbCore for historical reasons, but conceptually
it deserves to be its own library. This does introduce a (link-time) circular
dependency between lldbCore and lldbValueObject, which is unfortunate
but probably unavoidable because so many things in LLDB rely on
ValueObject. We already have cycles and these libraries are never built
as dylibs so while this doesn't improve the situation, it also doesn't
make things worse.

The header includes were updated with the following command:

```
find . -type f -exec sed -i.bak "s%include \"lldb/Core/ValueObject%include \"lldb/ValueObject/ValueObject%" '{}' \;
```

This allows IDEs to render LLDB expression diagnostics to their liking
without relying on characterprecise ASCII art from LLDB. It is exposed
as a versioned SBStructuredData object, since it is expected that this
may need to be tweaked based on actual usage.

and implement them for dwim-print (a.k.a. `p`) as an example.

The next step will be to expose them as structured data in
SBCommandReturnObject.

This is a cleanup that moves the API towards value semantics.