Was flagged in https://github.com/llvm/llvm-project/pull/124735
but done separately so it didn't get in the way of that.

As decided on
https://discourse.llvm.org/t/rfc-lets-document-and-enforce-a-minimum-python-version-for-lldb/82731.

LLDB 20 recommended `>= 3.8` but did not remove support for anything
earlier. Now we are in what will become LLDB 21, so I'm removing that
support and making
`>= 3.8` required.

See https://docs.python.org/3/c-api/apiabiversion.html#c.PY_VERSION_HEX
for the format of PY_VERSION_HEX.

Use PY_VERSION_HEX to simplify conditional compilation depending on the
Python version.

This also adds a static_assert to lldb-python to error out with a
meaningful diagnostic when you try building LLDB with an older Python
version in preparation for [1].

[1]
https://discourse.llvm.org/t/rfc-lets-document-and-enforce-a-minimum-python-version-for-lldb/82731/15

This fixes the deprecation warning for Py_SetPythonHome, which was
deprecated in Python 3.11. With this patch, when building against Python
3.8 or later, we now use Py_InitializeFromConfig instead.

Fixes #113475

Reverts llvm/llvm-project#114112 because this triggers a compile error:

```
no known conversion from 'str_type' (aka 'wchar_t *') to 'const char *' for 3rd argument
  221 | PyAPI_FUNC(PyStatus) PyConfig_SetBytesString(
      |                      ^
  222 |     PyConfig *config,
  223 |     wchar_t **config_str,
  224 |     const char *str);
      |     ~~~~~~~~~~~~~~~
1 error generated.

```

This fixes the deprecation warning for Py_SetPythonHome, which was
deprecated in Python 3.11. With this patch, when building against Python
3.8 or later, we now use Py_InitializeFromConfig instead.

Fixes #113475

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%" '{}' \;
```

If your arguments or option values are of a type that naturally uses one
of our common completion mechanisms, you will get completion for free.
But if you have your own custom values or if you want to do fancy things
like have `break set -s foo.dylib -n ba<TAB>` only complete on symbols
in foo.dylib, you can use this new mechanism to achieve that.

This patch re-lands #105449 and fixes the various test failures.

---------

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>