This adds new protocol types for the 'variables' request.
While implementing this, I removed the '$__lldb_extension' field we
returned on the 'variables' request, since I think all the data can be
retrieved from other DAP requests.
---------
Co-authored-by: Jonas Devlieghere <jonas@devlieghere.com>
This moves all the common settings of the launch and attach operations
into the `lldb_dap::protocol::Configuration`. These common settings
can be in both `launch` and `attach` requests and allows us to isolate
the DAP configuration operations into a single common location.
This is split out from #133624.
Replace Get{Signed,Unsigned} with GetInteger<T> and return std::optional
so you can distinguish between the value not being present and it being
explicitly set to the previous fail_value. All existing uses are
replaced by calling value_or(fail_value).
Continuation of #129818
Return a std::optional<bool> from GetBoolean so you can distinguish
between the value not being present and it being explicitly set to true
or false. All existing uses are replaced by calling
`value_or(fail_value`).
Motivated by #129753
