[lldb] Move QThreadSuffixSupported and QListThreadsInStopReply into llgs

These were in the shared llgs+platform code, but they only make sense
for llgs (as they deal with how the server reports information about
debugged processes).

GitOrigin-RevId: 2494243ed3f2ec2d7aba6e879fff47ff0ed71683
4 files changed