[lldb-dap][NFC] Fix deprecated SB API usages (#216006)
lldb-dap has accumulated over time several calls to deprecated SB API
functions. Since #215818 we actually emit the missing deprecation
warnings which breaks the lldb-dap build with -Werror. This patch
replaces the deprecated functions with the equivalent non-deprecated
version.
Note that this patch is intentionally NFC and I just added TODOs for the
missing error handling.
assisted-by: claude
